000001  /*
000002  ** 2001 September 15
000003  **
000004  ** The author disclaims copyright to this source code.  In place of
000005  ** a legal notice, here is a blessing:
000006  **
000007  **    May you do good and not evil.
000008  **    May you find forgiveness for yourself and forgive others.
000009  **    May you share freely, never taking more than you give.
000010  **
000011  *************************************************************************
000012  ** This file contains C code routines that are called by the SQLite parser
000013  ** when syntax rules are reduced.  The routines in this file handle the
000014  ** following kinds of SQL syntax:
000015  **
000016  **     CREATE TABLE
000017  **     DROP TABLE
000018  **     CREATE INDEX
000019  **     DROP INDEX
000020  **     creating ID lists
000021  **     BEGIN TRANSACTION
000022  **     COMMIT
000023  **     ROLLBACK
000024  */
000025  #include "sqliteInt.h"
000026  
000027  #ifndef SQLITE_OMIT_SHARED_CACHE
000028  /*
000029  ** The TableLock structure is only used by the sqlite3TableLock() and
000030  ** codeTableLocks() functions.
000031  */
000032  struct TableLock {
000033    int iDb;               /* The database containing the table to be locked */
000034    int iTab;              /* The root page of the table to be locked */
000035    u8 isWriteLock;        /* True for write lock.  False for a read lock */
000036    const char *zLockName; /* Name of the table */
000037  };
000038  
000039  /*
000040  ** Record the fact that we want to lock a table at run-time.  
000041  **
000042  ** The table to be locked has root page iTab and is found in database iDb.
000043  ** A read or a write lock can be taken depending on isWritelock.
000044  **
000045  ** This routine just records the fact that the lock is desired.  The
000046  ** code to make the lock occur is generated by a later call to
000047  ** codeTableLocks() which occurs during sqlite3FinishCoding().
000048  */
000049  void sqlite3TableLock(
000050    Parse *pParse,     /* Parsing context */
000051    int iDb,           /* Index of the database containing the table to lock */
000052    int iTab,          /* Root page number of the table to be locked */
000053    u8 isWriteLock,    /* True for a write lock */
000054    const char *zName  /* Name of the table to be locked */
000055  ){
000056    Parse *pToplevel = sqlite3ParseToplevel(pParse);
000057    int i;
000058    int nBytes;
000059    TableLock *p;
000060    assert( iDb>=0 );
000061  
000062    if( iDb==1 ) return;
000063    if( !sqlite3BtreeSharable(pParse->db->aDb[iDb].pBt) ) return;
000064    for(i=0; i<pToplevel->nTableLock; i++){
000065      p = &pToplevel->aTableLock[i];
000066      if( p->iDb==iDb && p->iTab==iTab ){
000067        p->isWriteLock = (p->isWriteLock || isWriteLock);
000068        return;
000069      }
000070    }
000071  
000072    nBytes = sizeof(TableLock) * (pToplevel->nTableLock+1);
000073    pToplevel->aTableLock =
000074        sqlite3DbReallocOrFree(pToplevel->db, pToplevel->aTableLock, nBytes);
000075    if( pToplevel->aTableLock ){
000076      p = &pToplevel->aTableLock[pToplevel->nTableLock++];
000077      p->iDb = iDb;
000078      p->iTab = iTab;
000079      p->isWriteLock = isWriteLock;
000080      p->zLockName = zName;
000081    }else{
000082      pToplevel->nTableLock = 0;
000083      sqlite3OomFault(pToplevel->db);
000084    }
000085  }
000086  
000087  /*
000088  ** Code an OP_TableLock instruction for each table locked by the
000089  ** statement (configured by calls to sqlite3TableLock()).
000090  */
000091  static void codeTableLocks(Parse *pParse){
000092    int i;
000093    Vdbe *pVdbe; 
000094  
000095    pVdbe = sqlite3GetVdbe(pParse);
000096    assert( pVdbe!=0 ); /* sqlite3GetVdbe cannot fail: VDBE already allocated */
000097  
000098    for(i=0; i<pParse->nTableLock; i++){
000099      TableLock *p = &pParse->aTableLock[i];
000100      int p1 = p->iDb;
000101      sqlite3VdbeAddOp4(pVdbe, OP_TableLock, p1, p->iTab, p->isWriteLock,
000102                        p->zLockName, P4_STATIC);
000103    }
000104  }
000105  #else
000106    #define codeTableLocks(x)
000107  #endif
000108  
000109  /*
000110  ** Return TRUE if the given yDbMask object is empty - if it contains no
000111  ** 1 bits.  This routine is used by the DbMaskAllZero() and DbMaskNotZero()
000112  ** macros when SQLITE_MAX_ATTACHED is greater than 30.
000113  */
000114  #if SQLITE_MAX_ATTACHED>30
000115  int sqlite3DbMaskAllZero(yDbMask m){
000116    int i;
000117    for(i=0; i<sizeof(yDbMask); i++) if( m[i] ) return 0;
000118    return 1;
000119  }
000120  #endif
000121  
000122  /*
000123  ** This routine is called after a single SQL statement has been
000124  ** parsed and a VDBE program to execute that statement has been
000125  ** prepared.  This routine puts the finishing touches on the
000126  ** VDBE program and resets the pParse structure for the next
000127  ** parse.
000128  **
000129  ** Note that if an error occurred, it might be the case that
000130  ** no VDBE code was generated.
000131  */
000132  void sqlite3FinishCoding(Parse *pParse){
000133    sqlite3 *db;
000134    Vdbe *v;
000135  
000136    assert( pParse->pToplevel==0 );
000137    db = pParse->db;
000138    if( pParse->nested ) return;
000139    if( db->mallocFailed || pParse->nErr ){
000140      if( pParse->rc==SQLITE_OK ) pParse->rc = SQLITE_ERROR;
000141      return;
000142    }
000143  
000144    /* Begin by generating some termination code at the end of the
000145    ** vdbe program
000146    */
000147    v = sqlite3GetVdbe(pParse);
000148    assert( !pParse->isMultiWrite 
000149         || sqlite3VdbeAssertMayAbort(v, pParse->mayAbort));
000150    if( v ){
000151      sqlite3VdbeAddOp0(v, OP_Halt);
000152  
000153  #if SQLITE_USER_AUTHENTICATION
000154      if( pParse->nTableLock>0 && db->init.busy==0 ){
000155        sqlite3UserAuthInit(db);
000156        if( db->auth.authLevel<UAUTH_User ){
000157          sqlite3ErrorMsg(pParse, "user not authenticated");
000158          pParse->rc = SQLITE_AUTH_USER;
000159          return;
000160        }
000161      }
000162  #endif
000163  
000164      /* The cookie mask contains one bit for each database file open.
000165      ** (Bit 0 is for main, bit 1 is for temp, and so forth.)  Bits are
000166      ** set for each database that is used.  Generate code to start a
000167      ** transaction on each used database and to verify the schema cookie
000168      ** on each used database.
000169      */
000170      if( db->mallocFailed==0 
000171       && (DbMaskNonZero(pParse->cookieMask) || pParse->pConstExpr)
000172      ){
000173        int iDb, i;
000174        assert( sqlite3VdbeGetOp(v, 0)->opcode==OP_Init );
000175        sqlite3VdbeJumpHere(v, 0);
000176        for(iDb=0; iDb<db->nDb; iDb++){
000177          Schema *pSchema;
000178          if( DbMaskTest(pParse->cookieMask, iDb)==0 ) continue;
000179          sqlite3VdbeUsesBtree(v, iDb);
000180          pSchema = db->aDb[iDb].pSchema;
000181          sqlite3VdbeAddOp4Int(v,
000182            OP_Transaction,                    /* Opcode */
000183            iDb,                               /* P1 */
000184            DbMaskTest(pParse->writeMask,iDb), /* P2 */
000185            pSchema->schema_cookie,            /* P3 */
000186            pSchema->iGeneration               /* P4 */
000187          );
000188          if( db->init.busy==0 ) sqlite3VdbeChangeP5(v, 1);
000189          VdbeComment((v,
000190                "usesStmtJournal=%d", pParse->mayAbort && pParse->isMultiWrite));
000191        }
000192  #ifndef SQLITE_OMIT_VIRTUALTABLE
000193        for(i=0; i<pParse->nVtabLock; i++){
000194          char *vtab = (char *)sqlite3GetVTable(db, pParse->apVtabLock[i]);
000195          sqlite3VdbeAddOp4(v, OP_VBegin, 0, 0, 0, vtab, P4_VTAB);
000196        }
000197        pParse->nVtabLock = 0;
000198  #endif
000199  
000200        /* Once all the cookies have been verified and transactions opened, 
000201        ** obtain the required table-locks. This is a no-op unless the 
000202        ** shared-cache feature is enabled.
000203        */
000204        codeTableLocks(pParse);
000205  
000206        /* Initialize any AUTOINCREMENT data structures required.
000207        */
000208        sqlite3AutoincrementBegin(pParse);
000209  
000210        /* Code constant expressions that where factored out of inner loops */
000211        if( pParse->pConstExpr ){
000212          ExprList *pEL = pParse->pConstExpr;
000213          pParse->okConstFactor = 0;
000214          for(i=0; i<pEL->nExpr; i++){
000215            sqlite3ExprCode(pParse, pEL->a[i].pExpr, pEL->a[i].u.iConstExprReg);
000216          }
000217        }
000218  
000219        /* Finally, jump back to the beginning of the executable code. */
000220        sqlite3VdbeGoto(v, 1);
000221      }
000222    }
000223  
000224  
000225    /* Get the VDBE program ready for execution
000226    */
000227    if( v && pParse->nErr==0 && !db->mallocFailed ){
000228      assert( pParse->iCacheLevel==0 );  /* Disables and re-enables match */
000229      /* A minimum of one cursor is required if autoincrement is used
000230      *  See ticket [a696379c1f08866] */
000231      if( pParse->pAinc!=0 && pParse->nTab==0 ) pParse->nTab = 1;
000232      sqlite3VdbeMakeReady(v, pParse);
000233      pParse->rc = SQLITE_DONE;
000234    }else{
000235      pParse->rc = SQLITE_ERROR;
000236    }
000237  }
000238  
000239  /*
000240  ** Run the parser and code generator recursively in order to generate
000241  ** code for the SQL statement given onto the end of the pParse context
000242  ** currently under construction.  When the parser is run recursively
000243  ** this way, the final OP_Halt is not appended and other initialization
000244  ** and finalization steps are omitted because those are handling by the
000245  ** outermost parser.
000246  **
000247  ** Not everything is nestable.  This facility is designed to permit
000248  ** INSERT, UPDATE, and DELETE operations against SQLITE_MASTER.  Use
000249  ** care if you decide to try to use this routine for some other purposes.
000250  */
000251  void sqlite3NestedParse(Parse *pParse, const char *zFormat, ...){
000252    va_list ap;
000253    char *zSql;
000254    char *zErrMsg = 0;
000255    sqlite3 *db = pParse->db;
000256    char saveBuf[PARSE_TAIL_SZ];
000257  
000258    if( pParse->nErr ) return;
000259    assert( pParse->nested<10 );  /* Nesting should only be of limited depth */
000260    va_start(ap, zFormat);
000261    zSql = sqlite3VMPrintf(db, zFormat, ap);
000262    va_end(ap);
000263    if( zSql==0 ){
000264      return;   /* A malloc must have failed */
000265    }
000266    pParse->nested++;
000267    memcpy(saveBuf, PARSE_TAIL(pParse), PARSE_TAIL_SZ);
000268    memset(PARSE_TAIL(pParse), 0, PARSE_TAIL_SZ);
000269    sqlite3RunParser(pParse, zSql, &zErrMsg);
000270    sqlite3DbFree(db, zErrMsg);
000271    sqlite3DbFree(db, zSql);
000272    memcpy(PARSE_TAIL(pParse), saveBuf, PARSE_TAIL_SZ);
000273    pParse->nested--;
000274  }
000275  
000276  #if SQLITE_USER_AUTHENTICATION
000277  /*
000278  ** Return TRUE if zTable is the name of the system table that stores the
000279  ** list of users and their access credentials.
000280  */
000281  int sqlite3UserAuthTable(const char *zTable){
000282    return sqlite3_stricmp(zTable, "sqlite_user")==0;
000283  }
000284  #endif
000285  
000286  /*
000287  ** Locate the in-memory structure that describes a particular database
000288  ** table given the name of that table and (optionally) the name of the
000289  ** database containing the table.  Return NULL if not found.
000290  **
000291  ** If zDatabase is 0, all databases are searched for the table and the
000292  ** first matching table is returned.  (No checking for duplicate table
000293  ** names is done.)  The search order is TEMP first, then MAIN, then any
000294  ** auxiliary databases added using the ATTACH command.
000295  **
000296  ** See also sqlite3LocateTable().
000297  */
000298  Table *sqlite3FindTable(sqlite3 *db, const char *zName, const char *zDatabase){
000299    Table *p = 0;
000300    int i;
000301  
000302    /* All mutexes are required for schema access.  Make sure we hold them. */
000303    assert( zDatabase!=0 || sqlite3BtreeHoldsAllMutexes(db) );
000304  #if SQLITE_USER_AUTHENTICATION
000305    /* Only the admin user is allowed to know that the sqlite_user table
000306    ** exists */
000307    if( db->auth.authLevel<UAUTH_Admin && sqlite3UserAuthTable(zName)!=0 ){
000308      return 0;
000309    }
000310  #endif
000311    while(1){
000312      for(i=OMIT_TEMPDB; i<db->nDb; i++){
000313        int j = (i<2) ? i^1 : i;   /* Search TEMP before MAIN */
000314        if( zDatabase==0 || sqlite3StrICmp(zDatabase, db->aDb[j].zDbSName)==0 ){
000315          assert( sqlite3SchemaMutexHeld(db, j, 0) );
000316          p = sqlite3HashFind(&db->aDb[j].pSchema->tblHash, zName);
000317          if( p ) return p;
000318        }
000319      }
000320      /* Not found.  If the name we were looking for was temp.sqlite_master
000321      ** then change the name to sqlite_temp_master and try again. */
000322      if( sqlite3StrICmp(zName, MASTER_NAME)!=0 ) break;
000323      if( sqlite3_stricmp(zDatabase, db->aDb[1].zDbSName)!=0 ) break;
000324      zName = TEMP_MASTER_NAME;
000325    }
000326    return 0;
000327  }
000328  
000329  /*
000330  ** Locate the in-memory structure that describes a particular database
000331  ** table given the name of that table and (optionally) the name of the
000332  ** database containing the table.  Return NULL if not found.  Also leave an
000333  ** error message in pParse->zErrMsg.
000334  **
000335  ** The difference between this routine and sqlite3FindTable() is that this
000336  ** routine leaves an error message in pParse->zErrMsg where
000337  ** sqlite3FindTable() does not.
000338  */
000339  Table *sqlite3LocateTable(
000340    Parse *pParse,         /* context in which to report errors */
000341    u32 flags,             /* LOCATE_VIEW or LOCATE_NOERR */
000342    const char *zName,     /* Name of the table we are looking for */
000343    const char *zDbase     /* Name of the database.  Might be NULL */
000344  ){
000345    Table *p;
000346  
000347    /* Read the database schema. If an error occurs, leave an error message
000348    ** and code in pParse and return NULL. */
000349    if( SQLITE_OK!=sqlite3ReadSchema(pParse) ){
000350      return 0;
000351    }
000352  
000353    p = sqlite3FindTable(pParse->db, zName, zDbase);
000354    if( p==0 ){
000355      const char *zMsg = flags & LOCATE_VIEW ? "no such view" : "no such table";
000356  #ifndef SQLITE_OMIT_VIRTUALTABLE
000357      if( sqlite3FindDbName(pParse->db, zDbase)<1 ){
000358        /* If zName is the not the name of a table in the schema created using
000359        ** CREATE, then check to see if it is the name of an virtual table that
000360        ** can be an eponymous virtual table. */
000361        Module *pMod = (Module*)sqlite3HashFind(&pParse->db->aModule, zName);
000362        if( pMod==0 && sqlite3_strnicmp(zName, "pragma_", 7)==0 ){
000363          pMod = sqlite3PragmaVtabRegister(pParse->db, zName);
000364        }
000365        if( pMod && sqlite3VtabEponymousTableInit(pParse, pMod) ){
000366          return pMod->pEpoTab;
000367        }
000368      }
000369  #endif
000370      if( (flags & LOCATE_NOERR)==0 ){
000371        if( zDbase ){
000372          sqlite3ErrorMsg(pParse, "%s: %s.%s", zMsg, zDbase, zName);
000373        }else{
000374          sqlite3ErrorMsg(pParse, "%s: %s", zMsg, zName);
000375        }
000376        pParse->checkSchema = 1;
000377      }
000378    }
000379  
000380    return p;
000381  }
000382  
000383  /*
000384  ** Locate the table identified by *p.
000385  **
000386  ** This is a wrapper around sqlite3LocateTable(). The difference between
000387  ** sqlite3LocateTable() and this function is that this function restricts
000388  ** the search to schema (p->pSchema) if it is not NULL. p->pSchema may be
000389  ** non-NULL if it is part of a view or trigger program definition. See
000390  ** sqlite3FixSrcList() for details.
000391  */
000392  Table *sqlite3LocateTableItem(
000393    Parse *pParse, 
000394    u32 flags,
000395    struct SrcList_item *p
000396  ){
000397    const char *zDb;
000398    assert( p->pSchema==0 || p->zDatabase==0 );
000399    if( p->pSchema ){
000400      int iDb = sqlite3SchemaToIndex(pParse->db, p->pSchema);
000401      zDb = pParse->db->aDb[iDb].zDbSName;
000402    }else{
000403      zDb = p->zDatabase;
000404    }
000405    return sqlite3LocateTable(pParse, flags, p->zName, zDb);
000406  }
000407  
000408  /*
000409  ** Locate the in-memory structure that describes 
000410  ** a particular index given the name of that index
000411  ** and the name of the database that contains the index.
000412  ** Return NULL if not found.
000413  **
000414  ** If zDatabase is 0, all databases are searched for the
000415  ** table and the first matching index is returned.  (No checking
000416  ** for duplicate index names is done.)  The search order is
000417  ** TEMP first, then MAIN, then any auxiliary databases added
000418  ** using the ATTACH command.
000419  */
000420  Index *sqlite3FindIndex(sqlite3 *db, const char *zName, const char *zDb){
000421    Index *p = 0;
000422    int i;
000423    /* All mutexes are required for schema access.  Make sure we hold them. */
000424    assert( zDb!=0 || sqlite3BtreeHoldsAllMutexes(db) );
000425    for(i=OMIT_TEMPDB; i<db->nDb; i++){
000426      int j = (i<2) ? i^1 : i;  /* Search TEMP before MAIN */
000427      Schema *pSchema = db->aDb[j].pSchema;
000428      assert( pSchema );
000429      if( zDb && sqlite3StrICmp(zDb, db->aDb[j].zDbSName) ) continue;
000430      assert( sqlite3SchemaMutexHeld(db, j, 0) );
000431      p = sqlite3HashFind(&pSchema->idxHash, zName);
000432      if( p ) break;
000433    }
000434    return p;
000435  }
000436  
000437  /*
000438  ** Reclaim the memory used by an index
000439  */
000440  static void freeIndex(sqlite3 *db, Index *p){
000441  #ifndef SQLITE_OMIT_ANALYZE
000442    sqlite3DeleteIndexSamples(db, p);
000443  #endif
000444    sqlite3ExprDelete(db, p->pPartIdxWhere);
000445    sqlite3ExprListDelete(db, p->aColExpr);
000446    sqlite3DbFree(db, p->zColAff);
000447    if( p->isResized ) sqlite3DbFree(db, (void *)p->azColl);
000448  #ifdef SQLITE_ENABLE_STAT3_OR_STAT4
000449    sqlite3_free(p->aiRowEst);
000450  #endif
000451    sqlite3DbFree(db, p);
000452  }
000453  
000454  /*
000455  ** For the index called zIdxName which is found in the database iDb,
000456  ** unlike that index from its Table then remove the index from
000457  ** the index hash table and free all memory structures associated
000458  ** with the index.
000459  */
000460  void sqlite3UnlinkAndDeleteIndex(sqlite3 *db, int iDb, const char *zIdxName){
000461    Index *pIndex;
000462    Hash *pHash;
000463  
000464    assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
000465    pHash = &db->aDb[iDb].pSchema->idxHash;
000466    pIndex = sqlite3HashInsert(pHash, zIdxName, 0);
000467    if( ALWAYS(pIndex) ){
000468      if( pIndex->pTable->pIndex==pIndex ){
000469        pIndex->pTable->pIndex = pIndex->pNext;
000470      }else{
000471        Index *p;
000472        /* Justification of ALWAYS();  The index must be on the list of
000473        ** indices. */
000474        p = pIndex->pTable->pIndex;
000475        while( ALWAYS(p) && p->pNext!=pIndex ){ p = p->pNext; }
000476        if( ALWAYS(p && p->pNext==pIndex) ){
000477          p->pNext = pIndex->pNext;
000478        }
000479      }
000480      freeIndex(db, pIndex);
000481    }
000482    db->flags |= SQLITE_InternChanges;
000483  }
000484  
000485  /*
000486  ** Look through the list of open database files in db->aDb[] and if
000487  ** any have been closed, remove them from the list.  Reallocate the
000488  ** db->aDb[] structure to a smaller size, if possible.
000489  **
000490  ** Entry 0 (the "main" database) and entry 1 (the "temp" database)
000491  ** are never candidates for being collapsed.
000492  */
000493  void sqlite3CollapseDatabaseArray(sqlite3 *db){
000494    int i, j;
000495    for(i=j=2; i<db->nDb; i++){
000496      struct Db *pDb = &db->aDb[i];
000497      if( pDb->pBt==0 ){
000498        sqlite3DbFree(db, pDb->zDbSName);
000499        pDb->zDbSName = 0;
000500        continue;
000501      }
000502      if( j<i ){
000503        db->aDb[j] = db->aDb[i];
000504      }
000505      j++;
000506    }
000507    db->nDb = j;
000508    if( db->nDb<=2 && db->aDb!=db->aDbStatic ){
000509      memcpy(db->aDbStatic, db->aDb, 2*sizeof(db->aDb[0]));
000510      sqlite3DbFree(db, db->aDb);
000511      db->aDb = db->aDbStatic;
000512    }
000513  }
000514  
000515  /*
000516  ** Reset the schema for the database at index iDb.  Also reset the
000517  ** TEMP schema.
000518  */
000519  void sqlite3ResetOneSchema(sqlite3 *db, int iDb){
000520    Db *pDb;
000521    assert( iDb<db->nDb );
000522  
000523    /* Case 1:  Reset the single schema identified by iDb */
000524    pDb = &db->aDb[iDb];
000525    assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
000526    assert( pDb->pSchema!=0 );
000527    sqlite3SchemaClear(pDb->pSchema);
000528  
000529    /* If any database other than TEMP is reset, then also reset TEMP
000530    ** since TEMP might be holding triggers that reference tables in the
000531    ** other database.
000532    */
000533    if( iDb!=1 ){
000534      pDb = &db->aDb[1];
000535      assert( pDb->pSchema!=0 );
000536      sqlite3SchemaClear(pDb->pSchema);
000537    }
000538    return;
000539  }
000540  
000541  /*
000542  ** Erase all schema information from all attached databases (including
000543  ** "main" and "temp") for a single database connection.
000544  */
000545  void sqlite3ResetAllSchemasOfConnection(sqlite3 *db){
000546    int i;
000547    sqlite3BtreeEnterAll(db);
000548    for(i=0; i<db->nDb; i++){
000549      Db *pDb = &db->aDb[i];
000550      if( pDb->pSchema ){
000551        sqlite3SchemaClear(pDb->pSchema);
000552      }
000553    }
000554    db->flags &= ~SQLITE_InternChanges;
000555    sqlite3VtabUnlockList(db);
000556    sqlite3BtreeLeaveAll(db);
000557    sqlite3CollapseDatabaseArray(db);
000558  }
000559  
000560  /*
000561  ** This routine is called when a commit occurs.
000562  */
000563  void sqlite3CommitInternalChanges(sqlite3 *db){
000564    db->flags &= ~SQLITE_InternChanges;
000565  }
000566  
000567  /*
000568  ** Delete memory allocated for the column names of a table or view (the
000569  ** Table.aCol[] array).
000570  */
000571  void sqlite3DeleteColumnNames(sqlite3 *db, Table *pTable){
000572    int i;
000573    Column *pCol;
000574    assert( pTable!=0 );
000575    if( (pCol = pTable->aCol)!=0 ){
000576      for(i=0; i<pTable->nCol; i++, pCol++){
000577        sqlite3DbFree(db, pCol->zName);
000578        sqlite3ExprDelete(db, pCol->pDflt);
000579        sqlite3DbFree(db, pCol->zColl);
000580      }
000581      sqlite3DbFree(db, pTable->aCol);
000582    }
000583  }
000584  
000585  /*
000586  ** Remove the memory data structures associated with the given
000587  ** Table.  No changes are made to disk by this routine.
000588  **
000589  ** This routine just deletes the data structure.  It does not unlink
000590  ** the table data structure from the hash table.  But it does destroy
000591  ** memory structures of the indices and foreign keys associated with 
000592  ** the table.
000593  **
000594  ** The db parameter is optional.  It is needed if the Table object 
000595  ** contains lookaside memory.  (Table objects in the schema do not use
000596  ** lookaside memory, but some ephemeral Table objects do.)  Or the
000597  ** db parameter can be used with db->pnBytesFreed to measure the memory
000598  ** used by the Table object.
000599  */
000600  static void SQLITE_NOINLINE deleteTable(sqlite3 *db, Table *pTable){
000601    Index *pIndex, *pNext;
000602    TESTONLY( int nLookaside; ) /* Used to verify lookaside not used for schema */
000603  
000604    /* Record the number of outstanding lookaside allocations in schema Tables
000605    ** prior to doing any free() operations.  Since schema Tables do not use
000606    ** lookaside, this number should not change. */
000607    TESTONLY( nLookaside = (db && (pTable->tabFlags & TF_Ephemeral)==0) ?
000608                           db->lookaside.nOut : 0 );
000609  
000610    /* Delete all indices associated with this table. */
000611    for(pIndex = pTable->pIndex; pIndex; pIndex=pNext){
000612      pNext = pIndex->pNext;
000613      assert( pIndex->pSchema==pTable->pSchema
000614           || (IsVirtual(pTable) && pIndex->idxType!=SQLITE_IDXTYPE_APPDEF) );
000615      if( (db==0 || db->pnBytesFreed==0) && !IsVirtual(pTable) ){
000616        char *zName = pIndex->zName; 
000617        TESTONLY ( Index *pOld = ) sqlite3HashInsert(
000618           &pIndex->pSchema->idxHash, zName, 0
000619        );
000620        assert( db==0 || sqlite3SchemaMutexHeld(db, 0, pIndex->pSchema) );
000621        assert( pOld==pIndex || pOld==0 );
000622      }
000623      freeIndex(db, pIndex);
000624    }
000625  
000626    /* Delete any foreign keys attached to this table. */
000627    sqlite3FkDelete(db, pTable);
000628  
000629    /* Delete the Table structure itself.
000630    */
000631    sqlite3DeleteColumnNames(db, pTable);
000632    sqlite3DbFree(db, pTable->zName);
000633    sqlite3DbFree(db, pTable->zColAff);
000634    sqlite3SelectDelete(db, pTable->pSelect);
000635    sqlite3ExprListDelete(db, pTable->pCheck);
000636  #ifndef SQLITE_OMIT_VIRTUALTABLE
000637    sqlite3VtabClear(db, pTable);
000638  #endif
000639    sqlite3DbFree(db, pTable);
000640  
000641    /* Verify that no lookaside memory was used by schema tables */
000642    assert( nLookaside==0 || nLookaside==db->lookaside.nOut );
000643  }
000644  void sqlite3DeleteTable(sqlite3 *db, Table *pTable){
000645    /* Do not delete the table until the reference count reaches zero. */
000646    if( !pTable ) return;
000647    if( ((!db || db->pnBytesFreed==0) && (--pTable->nTabRef)>0) ) return;
000648    deleteTable(db, pTable);
000649  }
000650  
000651  
000652  /*
000653  ** Unlink the given table from the hash tables and the delete the
000654  ** table structure with all its indices and foreign keys.
000655  */
000656  void sqlite3UnlinkAndDeleteTable(sqlite3 *db, int iDb, const char *zTabName){
000657    Table *p;
000658    Db *pDb;
000659  
000660    assert( db!=0 );
000661    assert( iDb>=0 && iDb<db->nDb );
000662    assert( zTabName );
000663    assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
000664    testcase( zTabName[0]==0 );  /* Zero-length table names are allowed */
000665    pDb = &db->aDb[iDb];
000666    p = sqlite3HashInsert(&pDb->pSchema->tblHash, zTabName, 0);
000667    sqlite3DeleteTable(db, p);
000668    db->flags |= SQLITE_InternChanges;
000669  }
000670  
000671  /*
000672  ** Given a token, return a string that consists of the text of that
000673  ** token.  Space to hold the returned string
000674  ** is obtained from sqliteMalloc() and must be freed by the calling
000675  ** function.
000676  **
000677  ** Any quotation marks (ex:  "name", 'name', [name], or `name`) that
000678  ** surround the body of the token are removed.
000679  **
000680  ** Tokens are often just pointers into the original SQL text and so
000681  ** are not \000 terminated and are not persistent.  The returned string
000682  ** is \000 terminated and is persistent.
000683  */
000684  char *sqlite3NameFromToken(sqlite3 *db, Token *pName){
000685    char *zName;
000686    if( pName ){
000687      zName = sqlite3DbStrNDup(db, (char*)pName->z, pName->n);
000688      sqlite3Dequote(zName);
000689    }else{
000690      zName = 0;
000691    }
000692    return zName;
000693  }
000694  
000695  /*
000696  ** Open the sqlite_master table stored in database number iDb for
000697  ** writing. The table is opened using cursor 0.
000698  */
000699  void sqlite3OpenMasterTable(Parse *p, int iDb){
000700    Vdbe *v = sqlite3GetVdbe(p);
000701    sqlite3TableLock(p, iDb, MASTER_ROOT, 1, MASTER_NAME);
000702    sqlite3VdbeAddOp4Int(v, OP_OpenWrite, 0, MASTER_ROOT, iDb, 5);
000703    if( p->nTab==0 ){
000704      p->nTab = 1;
000705    }
000706  }
000707  
000708  /*
000709  ** Parameter zName points to a nul-terminated buffer containing the name
000710  ** of a database ("main", "temp" or the name of an attached db). This
000711  ** function returns the index of the named database in db->aDb[], or
000712  ** -1 if the named db cannot be found.
000713  */
000714  int sqlite3FindDbName(sqlite3 *db, const char *zName){
000715    int i = -1;         /* Database number */
000716    if( zName ){
000717      Db *pDb;
000718      for(i=(db->nDb-1), pDb=&db->aDb[i]; i>=0; i--, pDb--){
000719        if( 0==sqlite3_stricmp(pDb->zDbSName, zName) ) break;
000720        /* "main" is always an acceptable alias for the primary database
000721        ** even if it has been renamed using SQLITE_DBCONFIG_MAINDBNAME. */
000722        if( i==0 && 0==sqlite3_stricmp("main", zName) ) break;
000723      }
000724    }
000725    return i;
000726  }
000727  
000728  /*
000729  ** The token *pName contains the name of a database (either "main" or
000730  ** "temp" or the name of an attached db). This routine returns the
000731  ** index of the named database in db->aDb[], or -1 if the named db 
000732  ** does not exist.
000733  */
000734  int sqlite3FindDb(sqlite3 *db, Token *pName){
000735    int i;                               /* Database number */
000736    char *zName;                         /* Name we are searching for */
000737    zName = sqlite3NameFromToken(db, pName);
000738    i = sqlite3FindDbName(db, zName);
000739    sqlite3DbFree(db, zName);
000740    return i;
000741  }
000742  
000743  /* The table or view or trigger name is passed to this routine via tokens
000744  ** pName1 and pName2. If the table name was fully qualified, for example:
000745  **
000746  ** CREATE TABLE xxx.yyy (...);
000747  ** 
000748  ** Then pName1 is set to "xxx" and pName2 "yyy". On the other hand if
000749  ** the table name is not fully qualified, i.e.:
000750  **
000751  ** CREATE TABLE yyy(...);
000752  **
000753  ** Then pName1 is set to "yyy" and pName2 is "".
000754  **
000755  ** This routine sets the *ppUnqual pointer to point at the token (pName1 or
000756  ** pName2) that stores the unqualified table name.  The index of the
000757  ** database "xxx" is returned.
000758  */
000759  int sqlite3TwoPartName(
000760    Parse *pParse,      /* Parsing and code generating context */
000761    Token *pName1,      /* The "xxx" in the name "xxx.yyy" or "xxx" */
000762    Token *pName2,      /* The "yyy" in the name "xxx.yyy" */
000763    Token **pUnqual     /* Write the unqualified object name here */
000764  ){
000765    int iDb;                    /* Database holding the object */
000766    sqlite3 *db = pParse->db;
000767  
000768    assert( pName2!=0 );
000769    if( pName2->n>0 ){
000770      if( db->init.busy ) {
000771        sqlite3ErrorMsg(pParse, "corrupt database");
000772        return -1;
000773      }
000774      *pUnqual = pName2;
000775      iDb = sqlite3FindDb(db, pName1);
000776      if( iDb<0 ){
000777        sqlite3ErrorMsg(pParse, "unknown database %T", pName1);
000778        return -1;
000779      }
000780    }else{
000781      assert( db->init.iDb==0 || db->init.busy || (db->flags & SQLITE_Vacuum)!=0);
000782      iDb = db->init.iDb;
000783      *pUnqual = pName1;
000784    }
000785    return iDb;
000786  }
000787  
000788  /*
000789  ** This routine is used to check if the UTF-8 string zName is a legal
000790  ** unqualified name for a new schema object (table, index, view or
000791  ** trigger). All names are legal except those that begin with the string
000792  ** "sqlite_" (in upper, lower or mixed case). This portion of the namespace
000793  ** is reserved for internal use.
000794  */
000795  int sqlite3CheckObjectName(Parse *pParse, const char *zName){
000796    if( !pParse->db->init.busy && pParse->nested==0 
000797            && (pParse->db->flags & SQLITE_WriteSchema)==0
000798            && 0==sqlite3StrNICmp(zName, "sqlite_", 7) ){
000799      sqlite3ErrorMsg(pParse, "object name reserved for internal use: %s", zName);
000800      return SQLITE_ERROR;
000801    }
000802    return SQLITE_OK;
000803  }
000804  
000805  /*
000806  ** Return the PRIMARY KEY index of a table
000807  */
000808  Index *sqlite3PrimaryKeyIndex(Table *pTab){
000809    Index *p;
000810    for(p=pTab->pIndex; p && !IsPrimaryKeyIndex(p); p=p->pNext){}
000811    return p;
000812  }
000813  
000814  /*
000815  ** Return the column of index pIdx that corresponds to table
000816  ** column iCol.  Return -1 if not found.
000817  */
000818  i16 sqlite3ColumnOfIndex(Index *pIdx, i16 iCol){
000819    int i;
000820    for(i=0; i<pIdx->nColumn; i++){
000821      if( iCol==pIdx->aiColumn[i] ) return i;
000822    }
000823    return -1;
000824  }
000825  
000826  /*
000827  ** Begin constructing a new table representation in memory.  This is
000828  ** the first of several action routines that get called in response
000829  ** to a CREATE TABLE statement.  In particular, this routine is called
000830  ** after seeing tokens "CREATE" and "TABLE" and the table name. The isTemp
000831  ** flag is true if the table should be stored in the auxiliary database
000832  ** file instead of in the main database file.  This is normally the case
000833  ** when the "TEMP" or "TEMPORARY" keyword occurs in between
000834  ** CREATE and TABLE.
000835  **
000836  ** The new table record is initialized and put in pParse->pNewTable.
000837  ** As more of the CREATE TABLE statement is parsed, additional action
000838  ** routines will be called to add more information to this record.
000839  ** At the end of the CREATE TABLE statement, the sqlite3EndTable() routine
000840  ** is called to complete the construction of the new table record.
000841  */
000842  void sqlite3StartTable(
000843    Parse *pParse,   /* Parser context */
000844    Token *pName1,   /* First part of the name of the table or view */
000845    Token *pName2,   /* Second part of the name of the table or view */
000846    int isTemp,      /* True if this is a TEMP table */
000847    int isView,      /* True if this is a VIEW */
000848    int isVirtual,   /* True if this is a VIRTUAL table */
000849    int noErr        /* Do nothing if table already exists */
000850  ){
000851    Table *pTable;
000852    char *zName = 0; /* The name of the new table */
000853    sqlite3 *db = pParse->db;
000854    Vdbe *v;
000855    int iDb;         /* Database number to create the table in */
000856    Token *pName;    /* Unqualified name of the table to create */
000857  
000858    if( db->init.busy && db->init.newTnum==1 ){
000859      /* Special case:  Parsing the sqlite_master or sqlite_temp_master schema */
000860      iDb = db->init.iDb;
000861      zName = sqlite3DbStrDup(db, SCHEMA_TABLE(iDb));
000862      pName = pName1;
000863    }else{
000864      /* The common case */
000865      iDb = sqlite3TwoPartName(pParse, pName1, pName2, &pName);
000866      if( iDb<0 ) return;
000867      if( !OMIT_TEMPDB && isTemp && pName2->n>0 && iDb!=1 ){
000868        /* If creating a temp table, the name may not be qualified. Unless 
000869        ** the database name is "temp" anyway.  */
000870        sqlite3ErrorMsg(pParse, "temporary table name must be unqualified");
000871        return;
000872      }
000873      if( !OMIT_TEMPDB && isTemp ) iDb = 1;
000874      zName = sqlite3NameFromToken(db, pName);
000875    }
000876    pParse->sNameToken = *pName;
000877    if( zName==0 ) return;
000878    if( SQLITE_OK!=sqlite3CheckObjectName(pParse, zName) ){
000879      goto begin_table_error;
000880    }
000881    if( db->init.iDb==1 ) isTemp = 1;
000882  #ifndef SQLITE_OMIT_AUTHORIZATION
000883    assert( isTemp==0 || isTemp==1 );
000884    assert( isView==0 || isView==1 );
000885    {
000886      static const u8 aCode[] = {
000887         SQLITE_CREATE_TABLE,
000888         SQLITE_CREATE_TEMP_TABLE,
000889         SQLITE_CREATE_VIEW,
000890         SQLITE_CREATE_TEMP_VIEW
000891      };
000892      char *zDb = db->aDb[iDb].zDbSName;
000893      if( sqlite3AuthCheck(pParse, SQLITE_INSERT, SCHEMA_TABLE(isTemp), 0, zDb) ){
000894        goto begin_table_error;
000895      }
000896      if( !isVirtual && sqlite3AuthCheck(pParse, (int)aCode[isTemp+2*isView],
000897                                         zName, 0, zDb) ){
000898        goto begin_table_error;
000899      }
000900    }
000901  #endif
000902  
000903    /* Make sure the new table name does not collide with an existing
000904    ** index or table name in the same database.  Issue an error message if
000905    ** it does. The exception is if the statement being parsed was passed
000906    ** to an sqlite3_declare_vtab() call. In that case only the column names
000907    ** and types will be used, so there is no need to test for namespace
000908    ** collisions.
000909    */
000910    if( !IN_DECLARE_VTAB ){
000911      char *zDb = db->aDb[iDb].zDbSName;
000912      if( SQLITE_OK!=sqlite3ReadSchema(pParse) ){
000913        goto begin_table_error;
000914      }
000915      pTable = sqlite3FindTable(db, zName, zDb);
000916      if( pTable ){
000917        if( !noErr ){
000918          sqlite3ErrorMsg(pParse, "table %T already exists", pName);
000919        }else{
000920          assert( !db->init.busy || CORRUPT_DB );
000921          sqlite3CodeVerifySchema(pParse, iDb);
000922        }
000923        goto begin_table_error;
000924      }
000925      if( sqlite3FindIndex(db, zName, zDb)!=0 ){
000926        sqlite3ErrorMsg(pParse, "there is already an index named %s", zName);
000927        goto begin_table_error;
000928      }
000929    }
000930  
000931    pTable = sqlite3DbMallocZero(db, sizeof(Table));
000932    if( pTable==0 ){
000933      assert( db->mallocFailed );
000934      pParse->rc = SQLITE_NOMEM_BKPT;
000935      pParse->nErr++;
000936      goto begin_table_error;
000937    }
000938    pTable->zName = zName;
000939    pTable->iPKey = -1;
000940    pTable->pSchema = db->aDb[iDb].pSchema;
000941    pTable->nTabRef = 1;
000942    pTable->nRowLogEst = 200; assert( 200==sqlite3LogEst(1048576) );
000943    assert( pParse->pNewTable==0 );
000944    pParse->pNewTable = pTable;
000945  
000946    /* If this is the magic sqlite_sequence table used by autoincrement,
000947    ** then record a pointer to this table in the main database structure
000948    ** so that INSERT can find the table easily.
000949    */
000950  #ifndef SQLITE_OMIT_AUTOINCREMENT
000951    if( !pParse->nested && strcmp(zName, "sqlite_sequence")==0 ){
000952      assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
000953      pTable->pSchema->pSeqTab = pTable;
000954    }
000955  #endif
000956  
000957    /* Begin generating the code that will insert the table record into
000958    ** the SQLITE_MASTER table.  Note in particular that we must go ahead
000959    ** and allocate the record number for the table entry now.  Before any
000960    ** PRIMARY KEY or UNIQUE keywords are parsed.  Those keywords will cause
000961    ** indices to be created and the table record must come before the 
000962    ** indices.  Hence, the record number for the table must be allocated
000963    ** now.
000964    */
000965    if( !db->init.busy && (v = sqlite3GetVdbe(pParse))!=0 ){
000966      int addr1;
000967      int fileFormat;
000968      int reg1, reg2, reg3;
000969      /* nullRow[] is an OP_Record encoding of a row containing 5 NULLs */
000970      static const char nullRow[] = { 6, 0, 0, 0, 0, 0 };
000971      sqlite3BeginWriteOperation(pParse, 1, iDb);
000972  
000973  #ifndef SQLITE_OMIT_VIRTUALTABLE
000974      if( isVirtual ){
000975        sqlite3VdbeAddOp0(v, OP_VBegin);
000976      }
000977  #endif
000978  
000979      /* If the file format and encoding in the database have not been set, 
000980      ** set them now.
000981      */
000982      reg1 = pParse->regRowid = ++pParse->nMem;
000983      reg2 = pParse->regRoot = ++pParse->nMem;
000984      reg3 = ++pParse->nMem;
000985      sqlite3VdbeAddOp3(v, OP_ReadCookie, iDb, reg3, BTREE_FILE_FORMAT);
000986      sqlite3VdbeUsesBtree(v, iDb);
000987      addr1 = sqlite3VdbeAddOp1(v, OP_If, reg3); VdbeCoverage(v);
000988      fileFormat = (db->flags & SQLITE_LegacyFileFmt)!=0 ?
000989                    1 : SQLITE_MAX_FILE_FORMAT;
000990      sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_FILE_FORMAT, fileFormat);
000991      sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_TEXT_ENCODING, ENC(db));
000992      sqlite3VdbeJumpHere(v, addr1);
000993  
000994      /* This just creates a place-holder record in the sqlite_master table.
000995      ** The record created does not contain anything yet.  It will be replaced
000996      ** by the real entry in code generated at sqlite3EndTable().
000997      **
000998      ** The rowid for the new entry is left in register pParse->regRowid.
000999      ** The root page number of the new table is left in reg pParse->regRoot.
001000      ** The rowid and root page number values are needed by the code that
001001      ** sqlite3EndTable will generate.
001002      */
001003  #if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_VIRTUALTABLE)
001004      if( isView || isVirtual ){
001005        sqlite3VdbeAddOp2(v, OP_Integer, 0, reg2);
001006      }else
001007  #endif
001008      {
001009        pParse->addrCrTab = sqlite3VdbeAddOp2(v, OP_CreateTable, iDb, reg2);
001010      }
001011      sqlite3OpenMasterTable(pParse, iDb);
001012      sqlite3VdbeAddOp2(v, OP_NewRowid, 0, reg1);
001013      sqlite3VdbeAddOp4(v, OP_Blob, 6, reg3, 0, nullRow, P4_STATIC);
001014      sqlite3VdbeAddOp3(v, OP_Insert, 0, reg3, reg1);
001015      sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
001016      sqlite3VdbeAddOp0(v, OP_Close);
001017    }
001018  
001019    /* Normal (non-error) return. */
001020    return;
001021  
001022    /* If an error occurs, we jump here */
001023  begin_table_error:
001024    sqlite3DbFree(db, zName);
001025    return;
001026  }
001027  
001028  /* Set properties of a table column based on the (magical)
001029  ** name of the column.
001030  */
001031  #if SQLITE_ENABLE_HIDDEN_COLUMNS
001032  void sqlite3ColumnPropertiesFromName(Table *pTab, Column *pCol){
001033    if( sqlite3_strnicmp(pCol->zName, "__hidden__", 10)==0 ){
001034      pCol->colFlags |= COLFLAG_HIDDEN;
001035    }else if( pTab && pCol!=pTab->aCol && (pCol[-1].colFlags & COLFLAG_HIDDEN) ){
001036      pTab->tabFlags |= TF_OOOHidden;
001037    }
001038  }
001039  #endif
001040  
001041  
001042  /*
001043  ** Add a new column to the table currently being constructed.
001044  **
001045  ** The parser calls this routine once for each column declaration
001046  ** in a CREATE TABLE statement.  sqlite3StartTable() gets called
001047  ** first to get things going.  Then this routine is called for each
001048  ** column.
001049  */
001050  void sqlite3AddColumn(Parse *pParse, Token *pName, Token *pType){
001051    Table *p;
001052    int i;
001053    char *z;
001054    char *zType;
001055    Column *pCol;
001056    sqlite3 *db = pParse->db;
001057    if( (p = pParse->pNewTable)==0 ) return;
001058  #if SQLITE_MAX_COLUMN
001059    if( p->nCol+1>db->aLimit[SQLITE_LIMIT_COLUMN] ){
001060      sqlite3ErrorMsg(pParse, "too many columns on %s", p->zName);
001061      return;
001062    }
001063  #endif
001064    z = sqlite3DbMallocRaw(db, pName->n + pType->n + 2);
001065    if( z==0 ) return;
001066    memcpy(z, pName->z, pName->n);
001067    z[pName->n] = 0;
001068    sqlite3Dequote(z);
001069    for(i=0; i<p->nCol; i++){
001070      if( sqlite3_stricmp(z, p->aCol[i].zName)==0 ){
001071        sqlite3ErrorMsg(pParse, "duplicate column name: %s", z);
001072        sqlite3DbFree(db, z);
001073        return;
001074      }
001075    }
001076    if( (p->nCol & 0x7)==0 ){
001077      Column *aNew;
001078      aNew = sqlite3DbRealloc(db,p->aCol,(p->nCol+8)*sizeof(p->aCol[0]));
001079      if( aNew==0 ){
001080        sqlite3DbFree(db, z);
001081        return;
001082      }
001083      p->aCol = aNew;
001084    }
001085    pCol = &p->aCol[p->nCol];
001086    memset(pCol, 0, sizeof(p->aCol[0]));
001087    pCol->zName = z;
001088    sqlite3ColumnPropertiesFromName(p, pCol);
001089   
001090    if( pType->n==0 ){
001091      /* If there is no type specified, columns have the default affinity
001092      ** 'BLOB'. */
001093      pCol->affinity = SQLITE_AFF_BLOB;
001094      pCol->szEst = 1;
001095    }else{
001096      zType = z + sqlite3Strlen30(z) + 1;
001097      memcpy(zType, pType->z, pType->n);
001098      zType[pType->n] = 0;
001099      sqlite3Dequote(zType);
001100      pCol->affinity = sqlite3AffinityType(zType, &pCol->szEst);
001101      pCol->colFlags |= COLFLAG_HASTYPE;
001102    }
001103    p->nCol++;
001104    pParse->constraintName.n = 0;
001105  }
001106  
001107  /*
001108  ** This routine is called by the parser while in the middle of
001109  ** parsing a CREATE TABLE statement.  A "NOT NULL" constraint has
001110  ** been seen on a column.  This routine sets the notNull flag on
001111  ** the column currently under construction.
001112  */
001113  void sqlite3AddNotNull(Parse *pParse, int onError){
001114    Table *p;
001115    p = pParse->pNewTable;
001116    if( p==0 || NEVER(p->nCol<1) ) return;
001117    p->aCol[p->nCol-1].notNull = (u8)onError;
001118  }
001119  
001120  /*
001121  ** Scan the column type name zType (length nType) and return the
001122  ** associated affinity type.
001123  **
001124  ** This routine does a case-independent search of zType for the 
001125  ** substrings in the following table. If one of the substrings is
001126  ** found, the corresponding affinity is returned. If zType contains
001127  ** more than one of the substrings, entries toward the top of 
001128  ** the table take priority. For example, if zType is 'BLOBINT', 
001129  ** SQLITE_AFF_INTEGER is returned.
001130  **
001131  ** Substring     | Affinity
001132  ** --------------------------------
001133  ** 'INT'         | SQLITE_AFF_INTEGER
001134  ** 'CHAR'        | SQLITE_AFF_TEXT
001135  ** 'CLOB'        | SQLITE_AFF_TEXT
001136  ** 'TEXT'        | SQLITE_AFF_TEXT
001137  ** 'BLOB'        | SQLITE_AFF_BLOB
001138  ** 'REAL'        | SQLITE_AFF_REAL
001139  ** 'FLOA'        | SQLITE_AFF_REAL
001140  ** 'DOUB'        | SQLITE_AFF_REAL
001141  **
001142  ** If none of the substrings in the above table are found,
001143  ** SQLITE_AFF_NUMERIC is returned.
001144  */
001145  char sqlite3AffinityType(const char *zIn, u8 *pszEst){
001146    u32 h = 0;
001147    char aff = SQLITE_AFF_NUMERIC;
001148    const char *zChar = 0;
001149  
001150    assert( zIn!=0 );
001151    while( zIn[0] ){
001152      h = (h<<8) + sqlite3UpperToLower[(*zIn)&0xff];
001153      zIn++;
001154      if( h==(('c'<<24)+('h'<<16)+('a'<<8)+'r') ){             /* CHAR */
001155        aff = SQLITE_AFF_TEXT;
001156        zChar = zIn;
001157      }else if( h==(('c'<<24)+('l'<<16)+('o'<<8)+'b') ){       /* CLOB */
001158        aff = SQLITE_AFF_TEXT;
001159      }else if( h==(('t'<<24)+('e'<<16)+('x'<<8)+'t') ){       /* TEXT */
001160        aff = SQLITE_AFF_TEXT;
001161      }else if( h==(('b'<<24)+('l'<<16)+('o'<<8)+'b')          /* BLOB */
001162          && (aff==SQLITE_AFF_NUMERIC || aff==SQLITE_AFF_REAL) ){
001163        aff = SQLITE_AFF_BLOB;
001164        if( zIn[0]=='(' ) zChar = zIn;
001165  #ifndef SQLITE_OMIT_FLOATING_POINT
001166      }else if( h==(('r'<<24)+('e'<<16)+('a'<<8)+'l')          /* REAL */
001167          && aff==SQLITE_AFF_NUMERIC ){
001168        aff = SQLITE_AFF_REAL;
001169      }else if( h==(('f'<<24)+('l'<<16)+('o'<<8)+'a')          /* FLOA */
001170          && aff==SQLITE_AFF_NUMERIC ){
001171        aff = SQLITE_AFF_REAL;
001172      }else if( h==(('d'<<24)+('o'<<16)+('u'<<8)+'b')          /* DOUB */
001173          && aff==SQLITE_AFF_NUMERIC ){
001174        aff = SQLITE_AFF_REAL;
001175  #endif
001176      }else if( (h&0x00FFFFFF)==(('i'<<16)+('n'<<8)+'t') ){    /* INT */
001177        aff = SQLITE_AFF_INTEGER;
001178        break;
001179      }
001180    }
001181  
001182    /* If pszEst is not NULL, store an estimate of the field size.  The
001183    ** estimate is scaled so that the size of an integer is 1.  */
001184    if( pszEst ){
001185      *pszEst = 1;   /* default size is approx 4 bytes */
001186      if( aff<SQLITE_AFF_NUMERIC ){
001187        if( zChar ){
001188          while( zChar[0] ){
001189            if( sqlite3Isdigit(zChar[0]) ){
001190              int v = 0;
001191              sqlite3GetInt32(zChar, &v);
001192              v = v/4 + 1;
001193              if( v>255 ) v = 255;
001194              *pszEst = v; /* BLOB(k), VARCHAR(k), CHAR(k) -> r=(k/4+1) */
001195              break;
001196            }
001197            zChar++;
001198          }
001199        }else{
001200          *pszEst = 5;   /* BLOB, TEXT, CLOB -> r=5  (approx 20 bytes)*/
001201        }
001202      }
001203    }
001204    return aff;
001205  }
001206  
001207  /*
001208  ** The expression is the default value for the most recently added column
001209  ** of the table currently under construction.
001210  **
001211  ** Default value expressions must be constant.  Raise an exception if this
001212  ** is not the case.
001213  **
001214  ** This routine is called by the parser while in the middle of
001215  ** parsing a CREATE TABLE statement.
001216  */
001217  void sqlite3AddDefaultValue(Parse *pParse, ExprSpan *pSpan){
001218    Table *p;
001219    Column *pCol;
001220    sqlite3 *db = pParse->db;
001221    p = pParse->pNewTable;
001222    if( p!=0 ){
001223      pCol = &(p->aCol[p->nCol-1]);
001224      if( !sqlite3ExprIsConstantOrFunction(pSpan->pExpr, db->init.busy) ){
001225        sqlite3ErrorMsg(pParse, "default value of column [%s] is not constant",
001226            pCol->zName);
001227      }else{
001228        /* A copy of pExpr is used instead of the original, as pExpr contains
001229        ** tokens that point to volatile memory. The 'span' of the expression
001230        ** is required by pragma table_info.
001231        */
001232        Expr x;
001233        sqlite3ExprDelete(db, pCol->pDflt);
001234        memset(&x, 0, sizeof(x));
001235        x.op = TK_SPAN;
001236        x.u.zToken = sqlite3DbStrNDup(db, (char*)pSpan->zStart,
001237                                      (int)(pSpan->zEnd - pSpan->zStart));
001238        x.pLeft = pSpan->pExpr;
001239        x.flags = EP_Skip;
001240        pCol->pDflt = sqlite3ExprDup(db, &x, EXPRDUP_REDUCE);
001241        sqlite3DbFree(db, x.u.zToken);
001242      }
001243    }
001244    sqlite3ExprDelete(db, pSpan->pExpr);
001245  }
001246  
001247  /*
001248  ** Backwards Compatibility Hack:
001249  ** 
001250  ** Historical versions of SQLite accepted strings as column names in
001251  ** indexes and PRIMARY KEY constraints and in UNIQUE constraints.  Example:
001252  **
001253  **     CREATE TABLE xyz(a,b,c,d,e,PRIMARY KEY('a'),UNIQUE('b','c' COLLATE trim)
001254  **     CREATE INDEX abc ON xyz('c','d' DESC,'e' COLLATE nocase DESC);
001255  **
001256  ** This is goofy.  But to preserve backwards compatibility we continue to
001257  ** accept it.  This routine does the necessary conversion.  It converts
001258  ** the expression given in its argument from a TK_STRING into a TK_ID
001259  ** if the expression is just a TK_STRING with an optional COLLATE clause.
001260  ** If the epxression is anything other than TK_STRING, the expression is
001261  ** unchanged.
001262  */
001263  static void sqlite3StringToId(Expr *p){
001264    if( p->op==TK_STRING ){
001265      p->op = TK_ID;
001266    }else if( p->op==TK_COLLATE && p->pLeft->op==TK_STRING ){
001267      p->pLeft->op = TK_ID;
001268    }
001269  }
001270  
001271  /*
001272  ** Designate the PRIMARY KEY for the table.  pList is a list of names 
001273  ** of columns that form the primary key.  If pList is NULL, then the
001274  ** most recently added column of the table is the primary key.
001275  **
001276  ** A table can have at most one primary key.  If the table already has
001277  ** a primary key (and this is the second primary key) then create an
001278  ** error.
001279  **
001280  ** If the PRIMARY KEY is on a single column whose datatype is INTEGER,
001281  ** then we will try to use that column as the rowid.  Set the Table.iPKey
001282  ** field of the table under construction to be the index of the
001283  ** INTEGER PRIMARY KEY column.  Table.iPKey is set to -1 if there is
001284  ** no INTEGER PRIMARY KEY.
001285  **
001286  ** If the key is not an INTEGER PRIMARY KEY, then create a unique
001287  ** index for the key.  No index is created for INTEGER PRIMARY KEYs.
001288  */
001289  void sqlite3AddPrimaryKey(
001290    Parse *pParse,    /* Parsing context */
001291    ExprList *pList,  /* List of field names to be indexed */
001292    int onError,      /* What to do with a uniqueness conflict */
001293    int autoInc,      /* True if the AUTOINCREMENT keyword is present */
001294    int sortOrder     /* SQLITE_SO_ASC or SQLITE_SO_DESC */
001295  ){
001296    Table *pTab = pParse->pNewTable;
001297    Column *pCol = 0;
001298    int iCol = -1, i;
001299    int nTerm;
001300    if( pTab==0 ) goto primary_key_exit;
001301    if( pTab->tabFlags & TF_HasPrimaryKey ){
001302      sqlite3ErrorMsg(pParse, 
001303        "table \"%s\" has more than one primary key", pTab->zName);
001304      goto primary_key_exit;
001305    }
001306    pTab->tabFlags |= TF_HasPrimaryKey;
001307    if( pList==0 ){
001308      iCol = pTab->nCol - 1;
001309      pCol = &pTab->aCol[iCol];
001310      pCol->colFlags |= COLFLAG_PRIMKEY;
001311      nTerm = 1;
001312    }else{
001313      nTerm = pList->nExpr;
001314      for(i=0; i<nTerm; i++){
001315        Expr *pCExpr = sqlite3ExprSkipCollate(pList->a[i].pExpr);
001316        assert( pCExpr!=0 );
001317        sqlite3StringToId(pCExpr);
001318        if( pCExpr->op==TK_ID ){
001319          const char *zCName = pCExpr->u.zToken;
001320          for(iCol=0; iCol<pTab->nCol; iCol++){
001321            if( sqlite3StrICmp(zCName, pTab->aCol[iCol].zName)==0 ){
001322              pCol = &pTab->aCol[iCol];
001323              pCol->colFlags |= COLFLAG_PRIMKEY;
001324              break;
001325            }
001326          }
001327        }
001328      }
001329    }
001330    if( nTerm==1
001331     && pCol
001332     && sqlite3StrICmp(sqlite3ColumnType(pCol,""), "INTEGER")==0
001333     && sortOrder!=SQLITE_SO_DESC
001334    ){
001335      pTab->iPKey = iCol;
001336      pTab->keyConf = (u8)onError;
001337      assert( autoInc==0 || autoInc==1 );
001338      pTab->tabFlags |= autoInc*TF_Autoincrement;
001339      if( pList ) pParse->iPkSortOrder = pList->a[0].sortOrder;
001340    }else if( autoInc ){
001341  #ifndef SQLITE_OMIT_AUTOINCREMENT
001342      sqlite3ErrorMsg(pParse, "AUTOINCREMENT is only allowed on an "
001343         "INTEGER PRIMARY KEY");
001344  #endif
001345    }else{
001346      sqlite3CreateIndex(pParse, 0, 0, 0, pList, onError, 0,
001347                             0, sortOrder, 0, SQLITE_IDXTYPE_PRIMARYKEY);
001348      pList = 0;
001349    }
001350  
001351  primary_key_exit:
001352    sqlite3ExprListDelete(pParse->db, pList);
001353    return;
001354  }
001355  
001356  /*
001357  ** Add a new CHECK constraint to the table currently under construction.
001358  */
001359  void sqlite3AddCheckConstraint(
001360    Parse *pParse,    /* Parsing context */
001361    Expr *pCheckExpr  /* The check expression */
001362  ){
001363  #ifndef SQLITE_OMIT_CHECK
001364    Table *pTab = pParse->pNewTable;
001365    sqlite3 *db = pParse->db;
001366    if( pTab && !IN_DECLARE_VTAB
001367     && !sqlite3BtreeIsReadonly(db->aDb[db->init.iDb].pBt)
001368    ){
001369      pTab->pCheck = sqlite3ExprListAppend(pParse, pTab->pCheck, pCheckExpr);
001370      if( pParse->constraintName.n ){
001371        sqlite3ExprListSetName(pParse, pTab->pCheck, &pParse->constraintName, 1);
001372      }
001373    }else
001374  #endif
001375    {
001376      sqlite3ExprDelete(pParse->db, pCheckExpr);
001377    }
001378  }
001379  
001380  /*
001381  ** Set the collation function of the most recently parsed table column
001382  ** to the CollSeq given.
001383  */
001384  void sqlite3AddCollateType(Parse *pParse, Token *pToken){
001385    Table *p;
001386    int i;
001387    char *zColl;              /* Dequoted name of collation sequence */
001388    sqlite3 *db;
001389  
001390    if( (p = pParse->pNewTable)==0 ) return;
001391    i = p->nCol-1;
001392    db = pParse->db;
001393    zColl = sqlite3NameFromToken(db, pToken);
001394    if( !zColl ) return;
001395  
001396    if( sqlite3LocateCollSeq(pParse, zColl) ){
001397      Index *pIdx;
001398      sqlite3DbFree(db, p->aCol[i].zColl);
001399      p->aCol[i].zColl = zColl;
001400    
001401      /* If the column is declared as "<name> PRIMARY KEY COLLATE <type>",
001402      ** then an index may have been created on this column before the
001403      ** collation type was added. Correct this if it is the case.
001404      */
001405      for(pIdx=p->pIndex; pIdx; pIdx=pIdx->pNext){
001406        assert( pIdx->nKeyCol==1 );
001407        if( pIdx->aiColumn[0]==i ){
001408          pIdx->azColl[0] = p->aCol[i].zColl;
001409        }
001410      }
001411    }else{
001412      sqlite3DbFree(db, zColl);
001413    }
001414  }
001415  
001416  /*
001417  ** This function returns the collation sequence for database native text
001418  ** encoding identified by the string zName, length nName.
001419  **
001420  ** If the requested collation sequence is not available, or not available
001421  ** in the database native encoding, the collation factory is invoked to
001422  ** request it. If the collation factory does not supply such a sequence,
001423  ** and the sequence is available in another text encoding, then that is
001424  ** returned instead.
001425  **
001426  ** If no versions of the requested collations sequence are available, or
001427  ** another error occurs, NULL is returned and an error message written into
001428  ** pParse.
001429  **
001430  ** This routine is a wrapper around sqlite3FindCollSeq().  This routine
001431  ** invokes the collation factory if the named collation cannot be found
001432  ** and generates an error message.
001433  **
001434  ** See also: sqlite3FindCollSeq(), sqlite3GetCollSeq()
001435  */
001436  CollSeq *sqlite3LocateCollSeq(Parse *pParse, const char *zName){
001437    sqlite3 *db = pParse->db;
001438    u8 enc = ENC(db);
001439    u8 initbusy = db->init.busy;
001440    CollSeq *pColl;
001441  
001442    pColl = sqlite3FindCollSeq(db, enc, zName, initbusy);
001443    if( !initbusy && (!pColl || !pColl->xCmp) ){
001444      pColl = sqlite3GetCollSeq(pParse, enc, pColl, zName);
001445    }
001446  
001447    return pColl;
001448  }
001449  
001450  
001451  /*
001452  ** Generate code that will increment the schema cookie.
001453  **
001454  ** The schema cookie is used to determine when the schema for the
001455  ** database changes.  After each schema change, the cookie value
001456  ** changes.  When a process first reads the schema it records the
001457  ** cookie.  Thereafter, whenever it goes to access the database,
001458  ** it checks the cookie to make sure the schema has not changed
001459  ** since it was last read.
001460  **
001461  ** This plan is not completely bullet-proof.  It is possible for
001462  ** the schema to change multiple times and for the cookie to be
001463  ** set back to prior value.  But schema changes are infrequent
001464  ** and the probability of hitting the same cookie value is only
001465  ** 1 chance in 2^32.  So we're safe enough.
001466  **
001467  ** IMPLEMENTATION-OF: R-34230-56049 SQLite automatically increments
001468  ** the schema-version whenever the schema changes.
001469  */
001470  void sqlite3ChangeCookie(Parse *pParse, int iDb){
001471    sqlite3 *db = pParse->db;
001472    Vdbe *v = pParse->pVdbe;
001473    assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
001474    sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_SCHEMA_VERSION, 
001475                      db->aDb[iDb].pSchema->schema_cookie+1);
001476  }
001477  
001478  /*
001479  ** Measure the number of characters needed to output the given
001480  ** identifier.  The number returned includes any quotes used
001481  ** but does not include the null terminator.
001482  **
001483  ** The estimate is conservative.  It might be larger that what is
001484  ** really needed.
001485  */
001486  static int identLength(const char *z){
001487    int n;
001488    for(n=0; *z; n++, z++){
001489      if( *z=='"' ){ n++; }
001490    }
001491    return n + 2;
001492  }
001493  
001494  /*
001495  ** The first parameter is a pointer to an output buffer. The second 
001496  ** parameter is a pointer to an integer that contains the offset at
001497  ** which to write into the output buffer. This function copies the
001498  ** nul-terminated string pointed to by the third parameter, zSignedIdent,
001499  ** to the specified offset in the buffer and updates *pIdx to refer
001500  ** to the first byte after the last byte written before returning.
001501  ** 
001502  ** If the string zSignedIdent consists entirely of alpha-numeric
001503  ** characters, does not begin with a digit and is not an SQL keyword,
001504  ** then it is copied to the output buffer exactly as it is. Otherwise,
001505  ** it is quoted using double-quotes.
001506  */
001507  static void identPut(char *z, int *pIdx, char *zSignedIdent){
001508    unsigned char *zIdent = (unsigned char*)zSignedIdent;
001509    int i, j, needQuote;
001510    i = *pIdx;
001511  
001512    for(j=0; zIdent[j]; j++){
001513      if( !sqlite3Isalnum(zIdent[j]) && zIdent[j]!='_' ) break;
001514    }
001515    needQuote = sqlite3Isdigit(zIdent[0])
001516              || sqlite3KeywordCode(zIdent, j)!=TK_ID
001517              || zIdent[j]!=0
001518              || j==0;
001519  
001520    if( needQuote ) z[i++] = '"';
001521    for(j=0; zIdent[j]; j++){
001522      z[i++] = zIdent[j];
001523      if( zIdent[j]=='"' ) z[i++] = '"';
001524    }
001525    if( needQuote ) z[i++] = '"';
001526    z[i] = 0;
001527    *pIdx = i;
001528  }
001529  
001530  /*
001531  ** Generate a CREATE TABLE statement appropriate for the given
001532  ** table.  Memory to hold the text of the statement is obtained
001533  ** from sqliteMalloc() and must be freed by the calling function.
001534  */
001535  static char *createTableStmt(sqlite3 *db, Table *p){
001536    int i, k, n;
001537    char *zStmt;
001538    char *zSep, *zSep2, *zEnd;
001539    Column *pCol;
001540    n = 0;
001541    for(pCol = p->aCol, i=0; i<p->nCol; i++, pCol++){
001542      n += identLength(pCol->zName) + 5;
001543    }
001544    n += identLength(p->zName);
001545    if( n<50 ){ 
001546      zSep = "";
001547      zSep2 = ",";
001548      zEnd = ")";
001549    }else{
001550      zSep = "\n  ";
001551      zSep2 = ",\n  ";
001552      zEnd = "\n)";
001553    }
001554    n += 35 + 6*p->nCol;
001555    zStmt = sqlite3DbMallocRaw(0, n);
001556    if( zStmt==0 ){
001557      sqlite3OomFault(db);
001558      return 0;
001559    }
001560    sqlite3_snprintf(n, zStmt, "CREATE TABLE ");
001561    k = sqlite3Strlen30(zStmt);
001562    identPut(zStmt, &k, p->zName);
001563    zStmt[k++] = '(';
001564    for(pCol=p->aCol, i=0; i<p->nCol; i++, pCol++){
001565      static const char * const azType[] = {
001566          /* SQLITE_AFF_BLOB    */ "",
001567          /* SQLITE_AFF_TEXT    */ " TEXT",
001568          /* SQLITE_AFF_NUMERIC */ " NUM",
001569          /* SQLITE_AFF_INTEGER */ " INT",
001570          /* SQLITE_AFF_REAL    */ " REAL"
001571      };
001572      int len;
001573      const char *zType;
001574  
001575      sqlite3_snprintf(n-k, &zStmt[k], zSep);
001576      k += sqlite3Strlen30(&zStmt[k]);
001577      zSep = zSep2;
001578      identPut(zStmt, &k, pCol->zName);
001579      assert( pCol->affinity-SQLITE_AFF_BLOB >= 0 );
001580      assert( pCol->affinity-SQLITE_AFF_BLOB < ArraySize(azType) );
001581      testcase( pCol->affinity==SQLITE_AFF_BLOB );
001582      testcase( pCol->affinity==SQLITE_AFF_TEXT );
001583      testcase( pCol->affinity==SQLITE_AFF_NUMERIC );
001584      testcase( pCol->affinity==SQLITE_AFF_INTEGER );
001585      testcase( pCol->affinity==SQLITE_AFF_REAL );
001586      
001587      zType = azType[pCol->affinity - SQLITE_AFF_BLOB];
001588      len = sqlite3Strlen30(zType);
001589      assert( pCol->affinity==SQLITE_AFF_BLOB 
001590              || pCol->affinity==sqlite3AffinityType(zType, 0) );
001591      memcpy(&zStmt[k], zType, len);
001592      k += len;
001593      assert( k<=n );
001594    }
001595    sqlite3_snprintf(n-k, &zStmt[k], "%s", zEnd);
001596    return zStmt;
001597  }
001598  
001599  /*
001600  ** Resize an Index object to hold N columns total.  Return SQLITE_OK
001601  ** on success and SQLITE_NOMEM on an OOM error.
001602  */
001603  static int resizeIndexObject(sqlite3 *db, Index *pIdx, int N){
001604    char *zExtra;
001605    int nByte;
001606    if( pIdx->nColumn>=N ) return SQLITE_OK;
001607    assert( pIdx->isResized==0 );
001608    nByte = (sizeof(char*) + sizeof(i16) + 1)*N;
001609    zExtra = sqlite3DbMallocZero(db, nByte);
001610    if( zExtra==0 ) return SQLITE_NOMEM_BKPT;
001611    memcpy(zExtra, pIdx->azColl, sizeof(char*)*pIdx->nColumn);
001612    pIdx->azColl = (const char**)zExtra;
001613    zExtra += sizeof(char*)*N;
001614    memcpy(zExtra, pIdx->aiColumn, sizeof(i16)*pIdx->nColumn);
001615    pIdx->aiColumn = (i16*)zExtra;
001616    zExtra += sizeof(i16)*N;
001617    memcpy(zExtra, pIdx->aSortOrder, pIdx->nColumn);
001618    pIdx->aSortOrder = (u8*)zExtra;
001619    pIdx->nColumn = N;
001620    pIdx->isResized = 1;
001621    return SQLITE_OK;
001622  }
001623  
001624  /*
001625  ** Estimate the total row width for a table.
001626  */
001627  static void estimateTableWidth(Table *pTab){
001628    unsigned wTable = 0;
001629    const Column *pTabCol;
001630    int i;
001631    for(i=pTab->nCol, pTabCol=pTab->aCol; i>0; i--, pTabCol++){
001632      wTable += pTabCol->szEst;
001633    }
001634    if( pTab->iPKey<0 ) wTable++;
001635    pTab->szTabRow = sqlite3LogEst(wTable*4);
001636  }
001637  
001638  /*
001639  ** Estimate the average size of a row for an index.
001640  */
001641  static void estimateIndexWidth(Index *pIdx){
001642    unsigned wIndex = 0;
001643    int i;
001644    const Column *aCol = pIdx->pTable->aCol;
001645    for(i=0; i<pIdx->nColumn; i++){
001646      i16 x = pIdx->aiColumn[i];
001647      assert( x<pIdx->pTable->nCol );
001648      wIndex += x<0 ? 1 : aCol[pIdx->aiColumn[i]].szEst;
001649    }
001650    pIdx->szIdxRow = sqlite3LogEst(wIndex*4);
001651  }
001652  
001653  /* Return true if value x is found any of the first nCol entries of aiCol[]
001654  */
001655  static int hasColumn(const i16 *aiCol, int nCol, int x){
001656    while( nCol-- > 0 ) if( x==*(aiCol++) ) return 1;
001657    return 0;
001658  }
001659  
001660  /*
001661  ** This routine runs at the end of parsing a CREATE TABLE statement that
001662  ** has a WITHOUT ROWID clause.  The job of this routine is to convert both
001663  ** internal schema data structures and the generated VDBE code so that they
001664  ** are appropriate for a WITHOUT ROWID table instead of a rowid table.
001665  ** Changes include:
001666  **
001667  **     (1)  Set all columns of the PRIMARY KEY schema object to be NOT NULL.
001668  **     (2)  Convert the OP_CreateTable into an OP_CreateIndex.  There is
001669  **          no rowid btree for a WITHOUT ROWID.  Instead, the canonical
001670  **          data storage is a covering index btree.
001671  **     (3)  Bypass the creation of the sqlite_master table entry
001672  **          for the PRIMARY KEY as the primary key index is now
001673  **          identified by the sqlite_master table entry of the table itself.
001674  **     (4)  Set the Index.tnum of the PRIMARY KEY Index object in the
001675  **          schema to the rootpage from the main table.
001676  **     (5)  Add all table columns to the PRIMARY KEY Index object
001677  **          so that the PRIMARY KEY is a covering index.  The surplus
001678  **          columns are part of KeyInfo.nXField and are not used for
001679  **          sorting or lookup or uniqueness checks.
001680  **     (6)  Replace the rowid tail on all automatically generated UNIQUE
001681  **          indices with the PRIMARY KEY columns.
001682  **
001683  ** For virtual tables, only (1) is performed.
001684  */
001685  static void convertToWithoutRowidTable(Parse *pParse, Table *pTab){
001686    Index *pIdx;
001687    Index *pPk;
001688    int nPk;
001689    int i, j;
001690    sqlite3 *db = pParse->db;
001691    Vdbe *v = pParse->pVdbe;
001692  
001693    /* Mark every PRIMARY KEY column as NOT NULL (except for imposter tables)
001694    */
001695    if( !db->init.imposterTable ){
001696      for(i=0; i<pTab->nCol; i++){
001697        if( (pTab->aCol[i].colFlags & COLFLAG_PRIMKEY)!=0 ){
001698          pTab->aCol[i].notNull = OE_Abort;
001699        }
001700      }
001701    }
001702  
001703    /* The remaining transformations only apply to b-tree tables, not to
001704    ** virtual tables */
001705    if( IN_DECLARE_VTAB ) return;
001706  
001707    /* Convert the OP_CreateTable opcode that would normally create the
001708    ** root-page for the table into an OP_CreateIndex opcode.  The index
001709    ** created will become the PRIMARY KEY index.
001710    */
001711    if( pParse->addrCrTab ){
001712      assert( v );
001713      sqlite3VdbeChangeOpcode(v, pParse->addrCrTab, OP_CreateIndex);
001714    }
001715  
001716    /* Locate the PRIMARY KEY index.  Or, if this table was originally
001717    ** an INTEGER PRIMARY KEY table, create a new PRIMARY KEY index. 
001718    */
001719    if( pTab->iPKey>=0 ){
001720      ExprList *pList;
001721      Token ipkToken;
001722      sqlite3TokenInit(&ipkToken, pTab->aCol[pTab->iPKey].zName);
001723      pList = sqlite3ExprListAppend(pParse, 0, 
001724                    sqlite3ExprAlloc(db, TK_ID, &ipkToken, 0));
001725      if( pList==0 ) return;
001726      pList->a[0].sortOrder = pParse->iPkSortOrder;
001727      assert( pParse->pNewTable==pTab );
001728      sqlite3CreateIndex(pParse, 0, 0, 0, pList, pTab->keyConf, 0, 0, 0, 0,
001729                         SQLITE_IDXTYPE_PRIMARYKEY);
001730      if( db->mallocFailed ) return;
001731      pPk = sqlite3PrimaryKeyIndex(pTab);
001732      pTab->iPKey = -1;
001733    }else{
001734      pPk = sqlite3PrimaryKeyIndex(pTab);
001735  
001736      /* Bypass the creation of the PRIMARY KEY btree and the sqlite_master
001737      ** table entry. This is only required if currently generating VDBE
001738      ** code for a CREATE TABLE (not when parsing one as part of reading
001739      ** a database schema).  */
001740      if( v ){
001741        assert( db->init.busy==0 );
001742        sqlite3VdbeChangeOpcode(v, pPk->tnum, OP_Goto);
001743      }
001744  
001745      /*
001746      ** Remove all redundant columns from the PRIMARY KEY.  For example, change
001747      ** "PRIMARY KEY(a,b,a,b,c,b,c,d)" into just "PRIMARY KEY(a,b,c,d)".  Later
001748      ** code assumes the PRIMARY KEY contains no repeated columns.
001749      */
001750      for(i=j=1; i<pPk->nKeyCol; i++){
001751        if( hasColumn(pPk->aiColumn, j, pPk->aiColumn[i]) ){
001752          pPk->nColumn--;
001753        }else{
001754          pPk->aiColumn[j++] = pPk->aiColumn[i];
001755        }
001756      }
001757      pPk->nKeyCol = j;
001758    }
001759    assert( pPk!=0 );
001760    pPk->isCovering = 1;
001761    if( !db->init.imposterTable ) pPk->uniqNotNull = 1;
001762    nPk = pPk->nKeyCol;
001763  
001764    /* The root page of the PRIMARY KEY is the table root page */
001765    pPk->tnum = pTab->tnum;
001766  
001767    /* Update the in-memory representation of all UNIQUE indices by converting
001768    ** the final rowid column into one or more columns of the PRIMARY KEY.
001769    */
001770    for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
001771      int n;
001772      if( IsPrimaryKeyIndex(pIdx) ) continue;
001773      for(i=n=0; i<nPk; i++){
001774        if( !hasColumn(pIdx->aiColumn, pIdx->nKeyCol, pPk->aiColumn[i]) ) n++;
001775      }
001776      if( n==0 ){
001777        /* This index is a superset of the primary key */
001778        pIdx->nColumn = pIdx->nKeyCol;
001779        continue;
001780      }
001781      if( resizeIndexObject(db, pIdx, pIdx->nKeyCol+n) ) return;
001782      for(i=0, j=pIdx->nKeyCol; i<nPk; i++){
001783        if( !hasColumn(pIdx->aiColumn, pIdx->nKeyCol, pPk->aiColumn[i]) ){
001784          pIdx->aiColumn[j] = pPk->aiColumn[i];
001785          pIdx->azColl[j] = pPk->azColl[i];
001786          j++;
001787        }
001788      }
001789      assert( pIdx->nColumn>=pIdx->nKeyCol+n );
001790      assert( pIdx->nColumn>=j );
001791    }
001792  
001793    /* Add all table columns to the PRIMARY KEY index
001794    */
001795    if( nPk<pTab->nCol ){
001796      if( resizeIndexObject(db, pPk, pTab->nCol) ) return;
001797      for(i=0, j=nPk; i<pTab->nCol; i++){
001798        if( !hasColumn(pPk->aiColumn, j, i) ){
001799          assert( j<pPk->nColumn );
001800          pPk->aiColumn[j] = i;
001801          pPk->azColl[j] = sqlite3StrBINARY;
001802          j++;
001803        }
001804      }
001805      assert( pPk->nColumn==j );
001806      assert( pTab->nCol==j );
001807    }else{
001808      pPk->nColumn = pTab->nCol;
001809    }
001810  }
001811  
001812  /*
001813  ** This routine is called to report the final ")" that terminates
001814  ** a CREATE TABLE statement.
001815  **
001816  ** The table structure that other action routines have been building
001817  ** is added to the internal hash tables, assuming no errors have
001818  ** occurred.
001819  **
001820  ** An entry for the table is made in the master table on disk, unless
001821  ** this is a temporary table or db->init.busy==1.  When db->init.busy==1
001822  ** it means we are reading the sqlite_master table because we just
001823  ** connected to the database or because the sqlite_master table has
001824  ** recently changed, so the entry for this table already exists in
001825  ** the sqlite_master table.  We do not want to create it again.
001826  **
001827  ** If the pSelect argument is not NULL, it means that this routine
001828  ** was called to create a table generated from a 
001829  ** "CREATE TABLE ... AS SELECT ..." statement.  The column names of
001830  ** the new table will match the result set of the SELECT.
001831  */
001832  void sqlite3EndTable(
001833    Parse *pParse,          /* Parse context */
001834    Token *pCons,           /* The ',' token after the last column defn. */
001835    Token *pEnd,            /* The ')' before options in the CREATE TABLE */
001836    u8 tabOpts,             /* Extra table options. Usually 0. */
001837    Select *pSelect         /* Select from a "CREATE ... AS SELECT" */
001838  ){
001839    Table *p;                 /* The new table */
001840    sqlite3 *db = pParse->db; /* The database connection */
001841    int iDb;                  /* Database in which the table lives */
001842    Index *pIdx;              /* An implied index of the table */
001843  
001844    if( pEnd==0 && pSelect==0 ){
001845      return;
001846    }
001847    assert( !db->mallocFailed );
001848    p = pParse->pNewTable;
001849    if( p==0 ) return;
001850  
001851    assert( !db->init.busy || !pSelect );
001852  
001853    /* If the db->init.busy is 1 it means we are reading the SQL off the
001854    ** "sqlite_master" or "sqlite_temp_master" table on the disk.
001855    ** So do not write to the disk again.  Extract the root page number
001856    ** for the table from the db->init.newTnum field.  (The page number
001857    ** should have been put there by the sqliteOpenCb routine.)
001858    **
001859    ** If the root page number is 1, that means this is the sqlite_master
001860    ** table itself.  So mark it read-only.
001861    */
001862    if( db->init.busy ){
001863      p->tnum = db->init.newTnum;
001864      if( p->tnum==1 ) p->tabFlags |= TF_Readonly;
001865    }
001866  
001867    /* Special processing for WITHOUT ROWID Tables */
001868    if( tabOpts & TF_WithoutRowid ){
001869      if( (p->tabFlags & TF_Autoincrement) ){
001870        sqlite3ErrorMsg(pParse,
001871            "AUTOINCREMENT not allowed on WITHOUT ROWID tables");
001872        return;
001873      }
001874      if( (p->tabFlags & TF_HasPrimaryKey)==0 ){
001875        sqlite3ErrorMsg(pParse, "PRIMARY KEY missing on table %s", p->zName);
001876      }else{
001877        p->tabFlags |= TF_WithoutRowid | TF_NoVisibleRowid;
001878        convertToWithoutRowidTable(pParse, p);
001879      }
001880    }
001881  
001882    iDb = sqlite3SchemaToIndex(db, p->pSchema);
001883  
001884  #ifndef SQLITE_OMIT_CHECK
001885    /* Resolve names in all CHECK constraint expressions.
001886    */
001887    if( p->pCheck ){
001888      sqlite3ResolveSelfReference(pParse, p, NC_IsCheck, 0, p->pCheck);
001889    }
001890  #endif /* !defined(SQLITE_OMIT_CHECK) */
001891  
001892    /* Estimate the average row size for the table and for all implied indices */
001893    estimateTableWidth(p);
001894    for(pIdx=p->pIndex; pIdx; pIdx=pIdx->pNext){
001895      estimateIndexWidth(pIdx);
001896    }
001897  
001898    /* If not initializing, then create a record for the new table
001899    ** in the SQLITE_MASTER table of the database.
001900    **
001901    ** If this is a TEMPORARY table, write the entry into the auxiliary
001902    ** file instead of into the main database file.
001903    */
001904    if( !db->init.busy ){
001905      int n;
001906      Vdbe *v;
001907      char *zType;    /* "view" or "table" */
001908      char *zType2;   /* "VIEW" or "TABLE" */
001909      char *zStmt;    /* Text of the CREATE TABLE or CREATE VIEW statement */
001910  
001911      v = sqlite3GetVdbe(pParse);
001912      if( NEVER(v==0) ) return;
001913  
001914      sqlite3VdbeAddOp1(v, OP_Close, 0);
001915  
001916      /* 
001917      ** Initialize zType for the new view or table.
001918      */
001919      if( p->pSelect==0 ){
001920        /* A regular table */
001921        zType = "table";
001922        zType2 = "TABLE";
001923  #ifndef SQLITE_OMIT_VIEW
001924      }else{
001925        /* A view */
001926        zType = "view";
001927        zType2 = "VIEW";
001928  #endif
001929      }
001930  
001931      /* If this is a CREATE TABLE xx AS SELECT ..., execute the SELECT
001932      ** statement to populate the new table. The root-page number for the
001933      ** new table is in register pParse->regRoot.
001934      **
001935      ** Once the SELECT has been coded by sqlite3Select(), it is in a
001936      ** suitable state to query for the column names and types to be used
001937      ** by the new table.
001938      **
001939      ** A shared-cache write-lock is not required to write to the new table,
001940      ** as a schema-lock must have already been obtained to create it. Since
001941      ** a schema-lock excludes all other database users, the write-lock would
001942      ** be redundant.
001943      */
001944      if( pSelect ){
001945        SelectDest dest;    /* Where the SELECT should store results */
001946        int regYield;       /* Register holding co-routine entry-point */
001947        int addrTop;        /* Top of the co-routine */
001948        int regRec;         /* A record to be insert into the new table */
001949        int regRowid;       /* Rowid of the next row to insert */
001950        int addrInsLoop;    /* Top of the loop for inserting rows */
001951        Table *pSelTab;     /* A table that describes the SELECT results */
001952  
001953        regYield = ++pParse->nMem;
001954        regRec = ++pParse->nMem;
001955        regRowid = ++pParse->nMem;
001956        assert(pParse->nTab==1);
001957        sqlite3MayAbort(pParse);
001958        sqlite3VdbeAddOp3(v, OP_OpenWrite, 1, pParse->regRoot, iDb);
001959        sqlite3VdbeChangeP5(v, OPFLAG_P2ISREG);
001960        pParse->nTab = 2;
001961        addrTop = sqlite3VdbeCurrentAddr(v) + 1;
001962        sqlite3VdbeAddOp3(v, OP_InitCoroutine, regYield, 0, addrTop);
001963        sqlite3SelectDestInit(&dest, SRT_Coroutine, regYield);
001964        sqlite3Select(pParse, pSelect, &dest);
001965        sqlite3VdbeEndCoroutine(v, regYield);
001966        sqlite3VdbeJumpHere(v, addrTop - 1);
001967        if( pParse->nErr ) return;
001968        pSelTab = sqlite3ResultSetOfSelect(pParse, pSelect);
001969        if( pSelTab==0 ) return;
001970        assert( p->aCol==0 );
001971        p->nCol = pSelTab->nCol;
001972        p->aCol = pSelTab->aCol;
001973        pSelTab->nCol = 0;
001974        pSelTab->aCol = 0;
001975        sqlite3DeleteTable(db, pSelTab);
001976        addrInsLoop = sqlite3VdbeAddOp1(v, OP_Yield, dest.iSDParm);
001977        VdbeCoverage(v);
001978        sqlite3VdbeAddOp3(v, OP_MakeRecord, dest.iSdst, dest.nSdst, regRec);
001979        sqlite3TableAffinity(v, p, 0);
001980        sqlite3VdbeAddOp2(v, OP_NewRowid, 1, regRowid);
001981        sqlite3VdbeAddOp3(v, OP_Insert, 1, regRec, regRowid);
001982        sqlite3VdbeGoto(v, addrInsLoop);
001983        sqlite3VdbeJumpHere(v, addrInsLoop);
001984        sqlite3VdbeAddOp1(v, OP_Close, 1);
001985      }
001986  
001987      /* Compute the complete text of the CREATE statement */
001988      if( pSelect ){
001989        zStmt = createTableStmt(db, p);
001990      }else{
001991        Token *pEnd2 = tabOpts ? &pParse->sLastToken : pEnd;
001992        n = (int)(pEnd2->z - pParse->sNameToken.z);
001993        if( pEnd2->z[0]!=';' ) n += pEnd2->n;
001994        zStmt = sqlite3MPrintf(db, 
001995            "CREATE %s %.*s", zType2, n, pParse->sNameToken.z
001996        );
001997      }
001998  
001999      /* A slot for the record has already been allocated in the 
002000      ** SQLITE_MASTER table.  We just need to update that slot with all
002001      ** the information we've collected.
002002      */
002003      sqlite3NestedParse(pParse,
002004        "UPDATE %Q.%s "
002005           "SET type='%s', name=%Q, tbl_name=%Q, rootpage=#%d, sql=%Q "
002006         "WHERE rowid=#%d",
002007        db->aDb[iDb].zDbSName, MASTER_NAME,
002008        zType,
002009        p->zName,
002010        p->zName,
002011        pParse->regRoot,
002012        zStmt,
002013        pParse->regRowid
002014      );
002015      sqlite3DbFree(db, zStmt);
002016      sqlite3ChangeCookie(pParse, iDb);
002017  
002018  #ifndef SQLITE_OMIT_AUTOINCREMENT
002019      /* Check to see if we need to create an sqlite_sequence table for
002020      ** keeping track of autoincrement keys.
002021      */
002022      if( (p->tabFlags & TF_Autoincrement)!=0 ){
002023        Db *pDb = &db->aDb[iDb];
002024        assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
002025        if( pDb->pSchema->pSeqTab==0 ){
002026          sqlite3NestedParse(pParse,
002027            "CREATE TABLE %Q.sqlite_sequence(name,seq)",
002028            pDb->zDbSName
002029          );
002030        }
002031      }
002032  #endif
002033  
002034      /* Reparse everything to update our internal data structures */
002035      sqlite3VdbeAddParseSchemaOp(v, iDb,
002036             sqlite3MPrintf(db, "tbl_name='%q' AND type!='trigger'", p->zName));
002037    }
002038  
002039  
002040    /* Add the table to the in-memory representation of the database.
002041    */
002042    if( db->init.busy ){
002043      Table *pOld;
002044      Schema *pSchema = p->pSchema;
002045      assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
002046      pOld = sqlite3HashInsert(&pSchema->tblHash, p->zName, p);
002047      if( pOld ){
002048        assert( p==pOld );  /* Malloc must have failed inside HashInsert() */
002049        sqlite3OomFault(db);
002050        return;
002051      }
002052      pParse->pNewTable = 0;
002053      db->flags |= SQLITE_InternChanges;
002054  
002055  #ifndef SQLITE_OMIT_ALTERTABLE
002056      if( !p->pSelect ){
002057        const char *zName = (const char *)pParse->sNameToken.z;
002058        int nName;
002059        assert( !pSelect && pCons && pEnd );
002060        if( pCons->z==0 ){
002061          pCons = pEnd;
002062        }
002063        nName = (int)((const char *)pCons->z - zName);
002064        p->addColOffset = 13 + sqlite3Utf8CharLen(zName, nName);
002065      }
002066  #endif
002067    }
002068  }
002069  
002070  #ifndef SQLITE_OMIT_VIEW
002071  /*
002072  ** The parser calls this routine in order to create a new VIEW
002073  */
002074  void sqlite3CreateView(
002075    Parse *pParse,     /* The parsing context */
002076    Token *pBegin,     /* The CREATE token that begins the statement */
002077    Token *pName1,     /* The token that holds the name of the view */
002078    Token *pName2,     /* The token that holds the name of the view */
002079    ExprList *pCNames, /* Optional list of view column names */
002080    Select *pSelect,   /* A SELECT statement that will become the new view */
002081    int isTemp,        /* TRUE for a TEMPORARY view */
002082    int noErr          /* Suppress error messages if VIEW already exists */
002083  ){
002084    Table *p;
002085    int n;
002086    const char *z;
002087    Token sEnd;
002088    DbFixer sFix;
002089    Token *pName = 0;
002090    int iDb;
002091    sqlite3 *db = pParse->db;
002092  
002093    if( pParse->nVar>0 ){
002094      sqlite3ErrorMsg(pParse, "parameters are not allowed in views");
002095      goto create_view_fail;
002096    }
002097    sqlite3StartTable(pParse, pName1, pName2, isTemp, 1, 0, noErr);
002098    p = pParse->pNewTable;
002099    if( p==0 || pParse->nErr ) goto create_view_fail;
002100    sqlite3TwoPartName(pParse, pName1, pName2, &pName);
002101    iDb = sqlite3SchemaToIndex(db, p->pSchema);
002102    sqlite3FixInit(&sFix, pParse, iDb, "view", pName);
002103    if( sqlite3FixSelect(&sFix, pSelect) ) goto create_view_fail;
002104  
002105    /* Make a copy of the entire SELECT statement that defines the view.
002106    ** This will force all the Expr.token.z values to be dynamically
002107    ** allocated rather than point to the input string - which means that
002108    ** they will persist after the current sqlite3_exec() call returns.
002109    */
002110    p->pSelect = sqlite3SelectDup(db, pSelect, EXPRDUP_REDUCE);
002111    p->pCheck = sqlite3ExprListDup(db, pCNames, EXPRDUP_REDUCE);
002112    if( db->mallocFailed ) goto create_view_fail;
002113  
002114    /* Locate the end of the CREATE VIEW statement.  Make sEnd point to
002115    ** the end.
002116    */
002117    sEnd = pParse->sLastToken;
002118    assert( sEnd.z[0]!=0 );
002119    if( sEnd.z[0]!=';' ){
002120      sEnd.z += sEnd.n;
002121    }
002122    sEnd.n = 0;
002123    n = (int)(sEnd.z - pBegin->z);
002124    assert( n>0 );
002125    z = pBegin->z;
002126    while( sqlite3Isspace(z[n-1]) ){ n--; }
002127    sEnd.z = &z[n-1];
002128    sEnd.n = 1;
002129  
002130    /* Use sqlite3EndTable() to add the view to the SQLITE_MASTER table */
002131    sqlite3EndTable(pParse, 0, &sEnd, 0, 0);
002132  
002133  create_view_fail:
002134    sqlite3SelectDelete(db, pSelect);
002135    sqlite3ExprListDelete(db, pCNames);
002136    return;
002137  }
002138  #endif /* SQLITE_OMIT_VIEW */
002139  
002140  #if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_VIRTUALTABLE)
002141  /*
002142  ** The Table structure pTable is really a VIEW.  Fill in the names of
002143  ** the columns of the view in the pTable structure.  Return the number
002144  ** of errors.  If an error is seen leave an error message in pParse->zErrMsg.
002145  */
002146  int sqlite3ViewGetColumnNames(Parse *pParse, Table *pTable){
002147    Table *pSelTab;   /* A fake table from which we get the result set */
002148    Select *pSel;     /* Copy of the SELECT that implements the view */
002149    int nErr = 0;     /* Number of errors encountered */
002150    int n;            /* Temporarily holds the number of cursors assigned */
002151    sqlite3 *db = pParse->db;  /* Database connection for malloc errors */
002152  #ifndef SQLITE_OMIT_AUTHORIZATION
002153    sqlite3_xauth xAuth;       /* Saved xAuth pointer */
002154  #endif
002155  
002156    assert( pTable );
002157  
002158  #ifndef SQLITE_OMIT_VIRTUALTABLE
002159    if( sqlite3VtabCallConnect(pParse, pTable) ){
002160      return SQLITE_ERROR;
002161    }
002162    if( IsVirtual(pTable) ) return 0;
002163  #endif
002164  
002165  #ifndef SQLITE_OMIT_VIEW
002166    /* A positive nCol means the columns names for this view are
002167    ** already known.
002168    */
002169    if( pTable->nCol>0 ) return 0;
002170  
002171    /* A negative nCol is a special marker meaning that we are currently
002172    ** trying to compute the column names.  If we enter this routine with
002173    ** a negative nCol, it means two or more views form a loop, like this:
002174    **
002175    **     CREATE VIEW one AS SELECT * FROM two;
002176    **     CREATE VIEW two AS SELECT * FROM one;
002177    **
002178    ** Actually, the error above is now caught prior to reaching this point.
002179    ** But the following test is still important as it does come up
002180    ** in the following:
002181    ** 
002182    **     CREATE TABLE main.ex1(a);
002183    **     CREATE TEMP VIEW ex1 AS SELECT a FROM ex1;
002184    **     SELECT * FROM temp.ex1;
002185    */
002186    if( pTable->nCol<0 ){
002187      sqlite3ErrorMsg(pParse, "view %s is circularly defined", pTable->zName);
002188      return 1;
002189    }
002190    assert( pTable->nCol>=0 );
002191  
002192    /* If we get this far, it means we need to compute the table names.
002193    ** Note that the call to sqlite3ResultSetOfSelect() will expand any
002194    ** "*" elements in the results set of the view and will assign cursors
002195    ** to the elements of the FROM clause.  But we do not want these changes
002196    ** to be permanent.  So the computation is done on a copy of the SELECT
002197    ** statement that defines the view.
002198    */
002199    assert( pTable->pSelect );
002200    pSel = sqlite3SelectDup(db, pTable->pSelect, 0);
002201    if( pSel ){
002202      n = pParse->nTab;
002203      sqlite3SrcListAssignCursors(pParse, pSel->pSrc);
002204      pTable->nCol = -1;
002205      db->lookaside.bDisable++;
002206  #ifndef SQLITE_OMIT_AUTHORIZATION
002207      xAuth = db->xAuth;
002208      db->xAuth = 0;
002209      pSelTab = sqlite3ResultSetOfSelect(pParse, pSel);
002210      db->xAuth = xAuth;
002211  #else
002212      pSelTab = sqlite3ResultSetOfSelect(pParse, pSel);
002213  #endif
002214      pParse->nTab = n;
002215      if( pTable->pCheck ){
002216        /* CREATE VIEW name(arglist) AS ...
002217        ** The names of the columns in the table are taken from
002218        ** arglist which is stored in pTable->pCheck.  The pCheck field
002219        ** normally holds CHECK constraints on an ordinary table, but for
002220        ** a VIEW it holds the list of column names.
002221        */
002222        sqlite3ColumnsFromExprList(pParse, pTable->pCheck, 
002223                                   &pTable->nCol, &pTable->aCol);
002224        if( db->mallocFailed==0 
002225         && pParse->nErr==0
002226         && pTable->nCol==pSel->pEList->nExpr
002227        ){
002228          sqlite3SelectAddColumnTypeAndCollation(pParse, pTable, pSel);
002229        }
002230      }else if( pSelTab ){
002231        /* CREATE VIEW name AS...  without an argument list.  Construct
002232        ** the column names from the SELECT statement that defines the view.
002233        */
002234        assert( pTable->aCol==0 );
002235        pTable->nCol = pSelTab->nCol;
002236        pTable->aCol = pSelTab->aCol;
002237        pSelTab->nCol = 0;
002238        pSelTab->aCol = 0;
002239        assert( sqlite3SchemaMutexHeld(db, 0, pTable->pSchema) );
002240      }else{
002241        pTable->nCol = 0;
002242        nErr++;
002243      }
002244      sqlite3DeleteTable(db, pSelTab);
002245      sqlite3SelectDelete(db, pSel);
002246      db->lookaside.bDisable--;
002247    } else {
002248      nErr++;
002249    }
002250    pTable->pSchema->schemaFlags |= DB_UnresetViews;
002251  #endif /* SQLITE_OMIT_VIEW */
002252    return nErr;  
002253  }
002254  #endif /* !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_VIRTUALTABLE) */
002255  
002256  #ifndef SQLITE_OMIT_VIEW
002257  /*
002258  ** Clear the column names from every VIEW in database idx.
002259  */
002260  static void sqliteViewResetAll(sqlite3 *db, int idx){
002261    HashElem *i;
002262    assert( sqlite3SchemaMutexHeld(db, idx, 0) );
002263    if( !DbHasProperty(db, idx, DB_UnresetViews) ) return;
002264    for(i=sqliteHashFirst(&db->aDb[idx].pSchema->tblHash); i;i=sqliteHashNext(i)){
002265      Table *pTab = sqliteHashData(i);
002266      if( pTab->pSelect ){
002267        sqlite3DeleteColumnNames(db, pTab);
002268        pTab->aCol = 0;
002269        pTab->nCol = 0;
002270      }
002271    }
002272    DbClearProperty(db, idx, DB_UnresetViews);
002273  }
002274  #else
002275  # define sqliteViewResetAll(A,B)
002276  #endif /* SQLITE_OMIT_VIEW */
002277  
002278  /*
002279  ** This function is called by the VDBE to adjust the internal schema
002280  ** used by SQLite when the btree layer moves a table root page. The
002281  ** root-page of a table or index in database iDb has changed from iFrom
002282  ** to iTo.
002283  **
002284  ** Ticket #1728:  The symbol table might still contain information
002285  ** on tables and/or indices that are the process of being deleted.
002286  ** If you are unlucky, one of those deleted indices or tables might
002287  ** have the same rootpage number as the real table or index that is
002288  ** being moved.  So we cannot stop searching after the first match 
002289  ** because the first match might be for one of the deleted indices
002290  ** or tables and not the table/index that is actually being moved.
002291  ** We must continue looping until all tables and indices with
002292  ** rootpage==iFrom have been converted to have a rootpage of iTo
002293  ** in order to be certain that we got the right one.
002294  */
002295  #ifndef SQLITE_OMIT_AUTOVACUUM
002296  void sqlite3RootPageMoved(sqlite3 *db, int iDb, int iFrom, int iTo){
002297    HashElem *pElem;
002298    Hash *pHash;
002299    Db *pDb;
002300  
002301    assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
002302    pDb = &db->aDb[iDb];
002303    pHash = &pDb->pSchema->tblHash;
002304    for(pElem=sqliteHashFirst(pHash); pElem; pElem=sqliteHashNext(pElem)){
002305      Table *pTab = sqliteHashData(pElem);
002306      if( pTab->tnum==iFrom ){
002307        pTab->tnum = iTo;
002308      }
002309    }
002310    pHash = &pDb->pSchema->idxHash;
002311    for(pElem=sqliteHashFirst(pHash); pElem; pElem=sqliteHashNext(pElem)){
002312      Index *pIdx = sqliteHashData(pElem);
002313      if( pIdx->tnum==iFrom ){
002314        pIdx->tnum = iTo;
002315      }
002316    }
002317  }
002318  #endif
002319  
002320  /*
002321  ** Write code to erase the table with root-page iTable from database iDb.
002322  ** Also write code to modify the sqlite_master table and internal schema
002323  ** if a root-page of another table is moved by the btree-layer whilst
002324  ** erasing iTable (this can happen with an auto-vacuum database).
002325  */ 
002326  static void destroyRootPage(Parse *pParse, int iTable, int iDb){
002327    Vdbe *v = sqlite3GetVdbe(pParse);
002328    int r1 = sqlite3GetTempReg(pParse);
002329    assert( iTable>1 );
002330    sqlite3VdbeAddOp3(v, OP_Destroy, iTable, r1, iDb);
002331    sqlite3MayAbort(pParse);
002332  #ifndef SQLITE_OMIT_AUTOVACUUM
002333    /* OP_Destroy stores an in integer r1. If this integer
002334    ** is non-zero, then it is the root page number of a table moved to
002335    ** location iTable. The following code modifies the sqlite_master table to
002336    ** reflect this.
002337    **
002338    ** The "#NNN" in the SQL is a special constant that means whatever value
002339    ** is in register NNN.  See grammar rules associated with the TK_REGISTER
002340    ** token for additional information.
002341    */
002342    sqlite3NestedParse(pParse, 
002343       "UPDATE %Q.%s SET rootpage=%d WHERE #%d AND rootpage=#%d",
002344       pParse->db->aDb[iDb].zDbSName, MASTER_NAME, iTable, r1, r1);
002345  #endif
002346    sqlite3ReleaseTempReg(pParse, r1);
002347  }
002348  
002349  /*
002350  ** Write VDBE code to erase table pTab and all associated indices on disk.
002351  ** Code to update the sqlite_master tables and internal schema definitions
002352  ** in case a root-page belonging to another table is moved by the btree layer
002353  ** is also added (this can happen with an auto-vacuum database).
002354  */
002355  static void destroyTable(Parse *pParse, Table *pTab){
002356  #ifdef SQLITE_OMIT_AUTOVACUUM
002357    Index *pIdx;
002358    int iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
002359    destroyRootPage(pParse, pTab->tnum, iDb);
002360    for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
002361      destroyRootPage(pParse, pIdx->tnum, iDb);
002362    }
002363  #else
002364    /* If the database may be auto-vacuum capable (if SQLITE_OMIT_AUTOVACUUM
002365    ** is not defined), then it is important to call OP_Destroy on the
002366    ** table and index root-pages in order, starting with the numerically 
002367    ** largest root-page number. This guarantees that none of the root-pages
002368    ** to be destroyed is relocated by an earlier OP_Destroy. i.e. if the
002369    ** following were coded:
002370    **
002371    ** OP_Destroy 4 0
002372    ** ...
002373    ** OP_Destroy 5 0
002374    **
002375    ** and root page 5 happened to be the largest root-page number in the
002376    ** database, then root page 5 would be moved to page 4 by the 
002377    ** "OP_Destroy 4 0" opcode. The subsequent "OP_Destroy 5 0" would hit
002378    ** a free-list page.
002379    */
002380    int iTab = pTab->tnum;
002381    int iDestroyed = 0;
002382  
002383    while( 1 ){
002384      Index *pIdx;
002385      int iLargest = 0;
002386  
002387      if( iDestroyed==0 || iTab<iDestroyed ){
002388        iLargest = iTab;
002389      }
002390      for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
002391        int iIdx = pIdx->tnum;
002392        assert( pIdx->pSchema==pTab->pSchema );
002393        if( (iDestroyed==0 || (iIdx<iDestroyed)) && iIdx>iLargest ){
002394          iLargest = iIdx;
002395        }
002396      }
002397      if( iLargest==0 ){
002398        return;
002399      }else{
002400        int iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
002401        assert( iDb>=0 && iDb<pParse->db->nDb );
002402        destroyRootPage(pParse, iLargest, iDb);
002403        iDestroyed = iLargest;
002404      }
002405    }
002406  #endif
002407  }
002408  
002409  /*
002410  ** Remove entries from the sqlite_statN tables (for N in (1,2,3))
002411  ** after a DROP INDEX or DROP TABLE command.
002412  */
002413  static void sqlite3ClearStatTables(
002414    Parse *pParse,         /* The parsing context */
002415    int iDb,               /* The database number */
002416    const char *zType,     /* "idx" or "tbl" */
002417    const char *zName      /* Name of index or table */
002418  ){
002419    int i;
002420    const char *zDbName = pParse->db->aDb[iDb].zDbSName;
002421    for(i=1; i<=4; i++){
002422      char zTab[24];
002423      sqlite3_snprintf(sizeof(zTab),zTab,"sqlite_stat%d",i);
002424      if( sqlite3FindTable(pParse->db, zTab, zDbName) ){
002425        sqlite3NestedParse(pParse,
002426          "DELETE FROM %Q.%s WHERE %s=%Q",
002427          zDbName, zTab, zType, zName
002428        );
002429      }
002430    }
002431  }
002432  
002433  /*
002434  ** Generate code to drop a table.
002435  */
002436  void sqlite3CodeDropTable(Parse *pParse, Table *pTab, int iDb, int isView){
002437    Vdbe *v;
002438    sqlite3 *db = pParse->db;
002439    Trigger *pTrigger;
002440    Db *pDb = &db->aDb[iDb];
002441  
002442    v = sqlite3GetVdbe(pParse);
002443    assert( v!=0 );
002444    sqlite3BeginWriteOperation(pParse, 1, iDb);
002445  
002446  #ifndef SQLITE_OMIT_VIRTUALTABLE
002447    if( IsVirtual(pTab) ){
002448      sqlite3VdbeAddOp0(v, OP_VBegin);
002449    }
002450  #endif
002451  
002452    /* Drop all triggers associated with the table being dropped. Code
002453    ** is generated to remove entries from sqlite_master and/or
002454    ** sqlite_temp_master if required.
002455    */
002456    pTrigger = sqlite3TriggerList(pParse, pTab);
002457    while( pTrigger ){
002458      assert( pTrigger->pSchema==pTab->pSchema || 
002459          pTrigger->pSchema==db->aDb[1].pSchema );
002460      sqlite3DropTriggerPtr(pParse, pTrigger);
002461      pTrigger = pTrigger->pNext;
002462    }
002463  
002464  #ifndef SQLITE_OMIT_AUTOINCREMENT
002465    /* Remove any entries of the sqlite_sequence table associated with
002466    ** the table being dropped. This is done before the table is dropped
002467    ** at the btree level, in case the sqlite_sequence table needs to
002468    ** move as a result of the drop (can happen in auto-vacuum mode).
002469    */
002470    if( pTab->tabFlags & TF_Autoincrement ){
002471      sqlite3NestedParse(pParse,
002472        "DELETE FROM %Q.sqlite_sequence WHERE name=%Q",
002473        pDb->zDbSName, pTab->zName
002474      );
002475    }
002476  #endif
002477  
002478    /* Drop all SQLITE_MASTER table and index entries that refer to the
002479    ** table. The program name loops through the master table and deletes
002480    ** every row that refers to a table of the same name as the one being
002481    ** dropped. Triggers are handled separately because a trigger can be
002482    ** created in the temp database that refers to a table in another
002483    ** database.
002484    */
002485    sqlite3NestedParse(pParse, 
002486        "DELETE FROM %Q.%s WHERE tbl_name=%Q and type!='trigger'",
002487        pDb->zDbSName, MASTER_NAME, pTab->zName);
002488    if( !isView && !IsVirtual(pTab) ){
002489      destroyTable(pParse, pTab);
002490    }
002491  
002492    /* Remove the table entry from SQLite's internal schema and modify
002493    ** the schema cookie.
002494    */
002495    if( IsVirtual(pTab) ){
002496      sqlite3VdbeAddOp4(v, OP_VDestroy, iDb, 0, 0, pTab->zName, 0);
002497    }
002498    sqlite3VdbeAddOp4(v, OP_DropTable, iDb, 0, 0, pTab->zName, 0);
002499    sqlite3ChangeCookie(pParse, iDb);
002500    sqliteViewResetAll(db, iDb);
002501  }
002502  
002503  /*
002504  ** This routine is called to do the work of a DROP TABLE statement.
002505  ** pName is the name of the table to be dropped.
002506  */
002507  void sqlite3DropTable(Parse *pParse, SrcList *pName, int isView, int noErr){
002508    Table *pTab;
002509    Vdbe *v;
002510    sqlite3 *db = pParse->db;
002511    int iDb;
002512  
002513    if( db->mallocFailed ){
002514      goto exit_drop_table;
002515    }
002516    assert( pParse->nErr==0 );
002517    assert( pName->nSrc==1 );
002518    if( sqlite3ReadSchema(pParse) ) goto exit_drop_table;
002519    if( noErr ) db->suppressErr++;
002520    assert( isView==0 || isView==LOCATE_VIEW );
002521    pTab = sqlite3LocateTableItem(pParse, isView, &pName->a[0]);
002522    if( noErr ) db->suppressErr--;
002523  
002524    if( pTab==0 ){
002525      if( noErr ) sqlite3CodeVerifyNamedSchema(pParse, pName->a[0].zDatabase);
002526      goto exit_drop_table;
002527    }
002528    iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
002529    assert( iDb>=0 && iDb<db->nDb );
002530  
002531    /* If pTab is a virtual table, call ViewGetColumnNames() to ensure
002532    ** it is initialized.
002533    */
002534    if( IsVirtual(pTab) && sqlite3ViewGetColumnNames(pParse, pTab) ){
002535      goto exit_drop_table;
002536    }
002537  #ifndef SQLITE_OMIT_AUTHORIZATION
002538    {
002539      int code;
002540      const char *zTab = SCHEMA_TABLE(iDb);
002541      const char *zDb = db->aDb[iDb].zDbSName;
002542      const char *zArg2 = 0;
002543      if( sqlite3AuthCheck(pParse, SQLITE_DELETE, zTab, 0, zDb)){
002544        goto exit_drop_table;
002545      }
002546      if( isView ){
002547        if( !OMIT_TEMPDB && iDb==1 ){
002548          code = SQLITE_DROP_TEMP_VIEW;
002549        }else{
002550          code = SQLITE_DROP_VIEW;
002551        }
002552  #ifndef SQLITE_OMIT_VIRTUALTABLE
002553      }else if( IsVirtual(pTab) ){
002554        code = SQLITE_DROP_VTABLE;
002555        zArg2 = sqlite3GetVTable(db, pTab)->pMod->zName;
002556  #endif
002557      }else{
002558        if( !OMIT_TEMPDB && iDb==1 ){
002559          code = SQLITE_DROP_TEMP_TABLE;
002560        }else{
002561          code = SQLITE_DROP_TABLE;
002562        }
002563      }
002564      if( sqlite3AuthCheck(pParse, code, pTab->zName, zArg2, zDb) ){
002565        goto exit_drop_table;
002566      }
002567      if( sqlite3AuthCheck(pParse, SQLITE_DELETE, pTab->zName, 0, zDb) ){
002568        goto exit_drop_table;
002569      }
002570    }
002571  #endif
002572    if( sqlite3StrNICmp(pTab->zName, "sqlite_", 7)==0 
002573      && sqlite3StrNICmp(pTab->zName, "sqlite_stat", 11)!=0 ){
002574      sqlite3ErrorMsg(pParse, "table %s may not be dropped", pTab->zName);
002575      goto exit_drop_table;
002576    }
002577  
002578  #ifndef SQLITE_OMIT_VIEW
002579    /* Ensure DROP TABLE is not used on a view, and DROP VIEW is not used
002580    ** on a table.
002581    */
002582    if( isView && pTab->pSelect==0 ){
002583      sqlite3ErrorMsg(pParse, "use DROP TABLE to delete table %s", pTab->zName);
002584      goto exit_drop_table;
002585    }
002586    if( !isView && pTab->pSelect ){
002587      sqlite3ErrorMsg(pParse, "use DROP VIEW to delete view %s", pTab->zName);
002588      goto exit_drop_table;
002589    }
002590  #endif
002591  
002592    /* Generate code to remove the table from the master table
002593    ** on disk.
002594    */
002595    v = sqlite3GetVdbe(pParse);
002596    if( v ){
002597      sqlite3BeginWriteOperation(pParse, 1, iDb);
002598      sqlite3ClearStatTables(pParse, iDb, "tbl", pTab->zName);
002599      sqlite3FkDropTable(pParse, pName, pTab);
002600      sqlite3CodeDropTable(pParse, pTab, iDb, isView);
002601    }
002602  
002603  exit_drop_table:
002604    sqlite3SrcListDelete(db, pName);
002605  }
002606  
002607  /*
002608  ** This routine is called to create a new foreign key on the table
002609  ** currently under construction.  pFromCol determines which columns
002610  ** in the current table point to the foreign key.  If pFromCol==0 then
002611  ** connect the key to the last column inserted.  pTo is the name of
002612  ** the table referred to (a.k.a the "parent" table).  pToCol is a list
002613  ** of tables in the parent pTo table.  flags contains all
002614  ** information about the conflict resolution algorithms specified
002615  ** in the ON DELETE, ON UPDATE and ON INSERT clauses.
002616  **
002617  ** An FKey structure is created and added to the table currently
002618  ** under construction in the pParse->pNewTable field.
002619  **
002620  ** The foreign key is set for IMMEDIATE processing.  A subsequent call
002621  ** to sqlite3DeferForeignKey() might change this to DEFERRED.
002622  */
002623  void sqlite3CreateForeignKey(
002624    Parse *pParse,       /* Parsing context */
002625    ExprList *pFromCol,  /* Columns in this table that point to other table */
002626    Token *pTo,          /* Name of the other table */
002627    ExprList *pToCol,    /* Columns in the other table */
002628    int flags            /* Conflict resolution algorithms. */
002629  ){
002630    sqlite3 *db = pParse->db;
002631  #ifndef SQLITE_OMIT_FOREIGN_KEY
002632    FKey *pFKey = 0;
002633    FKey *pNextTo;
002634    Table *p = pParse->pNewTable;
002635    int nByte;
002636    int i;
002637    int nCol;
002638    char *z;
002639  
002640    assert( pTo!=0 );
002641    if( p==0 || IN_DECLARE_VTAB ) goto fk_end;
002642    if( pFromCol==0 ){
002643      int iCol = p->nCol-1;
002644      if( NEVER(iCol<0) ) goto fk_end;
002645      if( pToCol && pToCol->nExpr!=1 ){
002646        sqlite3ErrorMsg(pParse, "foreign key on %s"
002647           " should reference only one column of table %T",
002648           p->aCol[iCol].zName, pTo);
002649        goto fk_end;
002650      }
002651      nCol = 1;
002652    }else if( pToCol && pToCol->nExpr!=pFromCol->nExpr ){
002653      sqlite3ErrorMsg(pParse,
002654          "number of columns in foreign key does not match the number of "
002655          "columns in the referenced table");
002656      goto fk_end;
002657    }else{
002658      nCol = pFromCol->nExpr;
002659    }
002660    nByte = sizeof(*pFKey) + (nCol-1)*sizeof(pFKey->aCol[0]) + pTo->n + 1;
002661    if( pToCol ){
002662      for(i=0; i<pToCol->nExpr; i++){
002663        nByte += sqlite3Strlen30(pToCol->a[i].zName) + 1;
002664      }
002665    }
002666    pFKey = sqlite3DbMallocZero(db, nByte );
002667    if( pFKey==0 ){
002668      goto fk_end;
002669    }
002670    pFKey->pFrom = p;
002671    pFKey->pNextFrom = p->pFKey;
002672    z = (char*)&pFKey->aCol[nCol];
002673    pFKey->zTo = z;
002674    memcpy(z, pTo->z, pTo->n);
002675    z[pTo->n] = 0;
002676    sqlite3Dequote(z);
002677    z += pTo->n+1;
002678    pFKey->nCol = nCol;
002679    if( pFromCol==0 ){
002680      pFKey->aCol[0].iFrom = p->nCol-1;
002681    }else{
002682      for(i=0; i<nCol; i++){
002683        int j;
002684        for(j=0; j<p->nCol; j++){
002685          if( sqlite3StrICmp(p->aCol[j].zName, pFromCol->a[i].zName)==0 ){
002686            pFKey->aCol[i].iFrom = j;
002687            break;
002688          }
002689        }
002690        if( j>=p->nCol ){
002691          sqlite3ErrorMsg(pParse, 
002692            "unknown column \"%s\" in foreign key definition", 
002693            pFromCol->a[i].zName);
002694          goto fk_end;
002695        }
002696      }
002697    }
002698    if( pToCol ){
002699      for(i=0; i<nCol; i++){
002700        int n = sqlite3Strlen30(pToCol->a[i].zName);
002701        pFKey->aCol[i].zCol = z;
002702        memcpy(z, pToCol->a[i].zName, n);
002703        z[n] = 0;
002704        z += n+1;
002705      }
002706    }
002707    pFKey->isDeferred = 0;
002708    pFKey->aAction[0] = (u8)(flags & 0xff);            /* ON DELETE action */
002709    pFKey->aAction[1] = (u8)((flags >> 8 ) & 0xff);    /* ON UPDATE action */
002710  
002711    assert( sqlite3SchemaMutexHeld(db, 0, p->pSchema) );
002712    pNextTo = (FKey *)sqlite3HashInsert(&p->pSchema->fkeyHash, 
002713        pFKey->zTo, (void *)pFKey
002714    );
002715    if( pNextTo==pFKey ){
002716      sqlite3OomFault(db);
002717      goto fk_end;
002718    }
002719    if( pNextTo ){
002720      assert( pNextTo->pPrevTo==0 );
002721      pFKey->pNextTo = pNextTo;
002722      pNextTo->pPrevTo = pFKey;
002723    }
002724  
002725    /* Link the foreign key to the table as the last step.
002726    */
002727    p->pFKey = pFKey;
002728    pFKey = 0;
002729  
002730  fk_end:
002731    sqlite3DbFree(db, pFKey);
002732  #endif /* !defined(SQLITE_OMIT_FOREIGN_KEY) */
002733    sqlite3ExprListDelete(db, pFromCol);
002734    sqlite3ExprListDelete(db, pToCol);
002735  }
002736  
002737  /*
002738  ** This routine is called when an INITIALLY IMMEDIATE or INITIALLY DEFERRED
002739  ** clause is seen as part of a foreign key definition.  The isDeferred
002740  ** parameter is 1 for INITIALLY DEFERRED and 0 for INITIALLY IMMEDIATE.
002741  ** The behavior of the most recently created foreign key is adjusted
002742  ** accordingly.
002743  */
002744  void sqlite3DeferForeignKey(Parse *pParse, int isDeferred){
002745  #ifndef SQLITE_OMIT_FOREIGN_KEY
002746    Table *pTab;
002747    FKey *pFKey;
002748    if( (pTab = pParse->pNewTable)==0 || (pFKey = pTab->pFKey)==0 ) return;
002749    assert( isDeferred==0 || isDeferred==1 ); /* EV: R-30323-21917 */
002750    pFKey->isDeferred = (u8)isDeferred;
002751  #endif
002752  }
002753  
002754  /*
002755  ** Generate code that will erase and refill index *pIdx.  This is
002756  ** used to initialize a newly created index or to recompute the
002757  ** content of an index in response to a REINDEX command.
002758  **
002759  ** if memRootPage is not negative, it means that the index is newly
002760  ** created.  The register specified by memRootPage contains the
002761  ** root page number of the index.  If memRootPage is negative, then
002762  ** the index already exists and must be cleared before being refilled and
002763  ** the root page number of the index is taken from pIndex->tnum.
002764  */
002765  static void sqlite3RefillIndex(Parse *pParse, Index *pIndex, int memRootPage){
002766    Table *pTab = pIndex->pTable;  /* The table that is indexed */
002767    int iTab = pParse->nTab++;     /* Btree cursor used for pTab */
002768    int iIdx = pParse->nTab++;     /* Btree cursor used for pIndex */
002769    int iSorter;                   /* Cursor opened by OpenSorter (if in use) */
002770    int addr1;                     /* Address of top of loop */
002771    int addr2;                     /* Address to jump to for next iteration */
002772    int tnum;                      /* Root page of index */
002773    int iPartIdxLabel;             /* Jump to this label to skip a row */
002774    Vdbe *v;                       /* Generate code into this virtual machine */
002775    KeyInfo *pKey;                 /* KeyInfo for index */
002776    int regRecord;                 /* Register holding assembled index record */
002777    sqlite3 *db = pParse->db;      /* The database connection */
002778    int iDb = sqlite3SchemaToIndex(db, pIndex->pSchema);
002779  
002780  #ifndef SQLITE_OMIT_AUTHORIZATION
002781    if( sqlite3AuthCheck(pParse, SQLITE_REINDEX, pIndex->zName, 0,
002782        db->aDb[iDb].zDbSName ) ){
002783      return;
002784    }
002785  #endif
002786  
002787    /* Require a write-lock on the table to perform this operation */
002788    sqlite3TableLock(pParse, iDb, pTab->tnum, 1, pTab->zName);
002789  
002790    v = sqlite3GetVdbe(pParse);
002791    if( v==0 ) return;
002792    if( memRootPage>=0 ){
002793      tnum = memRootPage;
002794    }else{
002795      tnum = pIndex->tnum;
002796    }
002797    pKey = sqlite3KeyInfoOfIndex(pParse, pIndex);
002798    assert( pKey!=0 || db->mallocFailed || pParse->nErr );
002799  
002800    /* Open the sorter cursor if we are to use one. */
002801    iSorter = pParse->nTab++;
002802    sqlite3VdbeAddOp4(v, OP_SorterOpen, iSorter, 0, pIndex->nKeyCol, (char*)
002803                      sqlite3KeyInfoRef(pKey), P4_KEYINFO);
002804  
002805    /* Open the table. Loop through all rows of the table, inserting index
002806    ** records into the sorter. */
002807    sqlite3OpenTable(pParse, iTab, iDb, pTab, OP_OpenRead);
002808    addr1 = sqlite3VdbeAddOp2(v, OP_Rewind, iTab, 0); VdbeCoverage(v);
002809    regRecord = sqlite3GetTempReg(pParse);
002810  
002811    sqlite3GenerateIndexKey(pParse,pIndex,iTab,regRecord,0,&iPartIdxLabel,0,0);
002812    sqlite3VdbeAddOp2(v, OP_SorterInsert, iSorter, regRecord);
002813    sqlite3ResolvePartIdxLabel(pParse, iPartIdxLabel);
002814    sqlite3VdbeAddOp2(v, OP_Next, iTab, addr1+1); VdbeCoverage(v);
002815    sqlite3VdbeJumpHere(v, addr1);
002816    if( memRootPage<0 ) sqlite3VdbeAddOp2(v, OP_Clear, tnum, iDb);
002817    sqlite3VdbeAddOp4(v, OP_OpenWrite, iIdx, tnum, iDb, 
002818                      (char *)pKey, P4_KEYINFO);
002819    sqlite3VdbeChangeP5(v, OPFLAG_BULKCSR|((memRootPage>=0)?OPFLAG_P2ISREG:0));
002820  
002821    addr1 = sqlite3VdbeAddOp2(v, OP_SorterSort, iSorter, 0); VdbeCoverage(v);
002822    if( IsUniqueIndex(pIndex) ){
002823      int j2 = sqlite3VdbeCurrentAddr(v) + 3;
002824      sqlite3VdbeGoto(v, j2);
002825      addr2 = sqlite3VdbeCurrentAddr(v);
002826      sqlite3VdbeAddOp4Int(v, OP_SorterCompare, iSorter, j2, regRecord,
002827                           pIndex->nKeyCol); VdbeCoverage(v);
002828      sqlite3UniqueConstraint(pParse, OE_Abort, pIndex);
002829    }else{
002830      addr2 = sqlite3VdbeCurrentAddr(v);
002831    }
002832    sqlite3VdbeAddOp3(v, OP_SorterData, iSorter, regRecord, iIdx);
002833    sqlite3VdbeAddOp3(v, OP_Last, iIdx, 0, -1);
002834    sqlite3VdbeAddOp2(v, OP_IdxInsert, iIdx, regRecord);
002835    sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT);
002836    sqlite3ReleaseTempReg(pParse, regRecord);
002837    sqlite3VdbeAddOp2(v, OP_SorterNext, iSorter, addr2); VdbeCoverage(v);
002838    sqlite3VdbeJumpHere(v, addr1);
002839  
002840    sqlite3VdbeAddOp1(v, OP_Close, iTab);
002841    sqlite3VdbeAddOp1(v, OP_Close, iIdx);
002842    sqlite3VdbeAddOp1(v, OP_Close, iSorter);
002843  }
002844  
002845  /*
002846  ** Allocate heap space to hold an Index object with nCol columns.
002847  **
002848  ** Increase the allocation size to provide an extra nExtra bytes
002849  ** of 8-byte aligned space after the Index object and return a
002850  ** pointer to this extra space in *ppExtra.
002851  */
002852  Index *sqlite3AllocateIndexObject(
002853    sqlite3 *db,         /* Database connection */
002854    i16 nCol,            /* Total number of columns in the index */
002855    int nExtra,          /* Number of bytes of extra space to alloc */
002856    char **ppExtra       /* Pointer to the "extra" space */
002857  ){
002858    Index *p;            /* Allocated index object */
002859    int nByte;           /* Bytes of space for Index object + arrays */
002860  
002861    nByte = ROUND8(sizeof(Index)) +              /* Index structure  */
002862            ROUND8(sizeof(char*)*nCol) +         /* Index.azColl     */
002863            ROUND8(sizeof(LogEst)*(nCol+1) +     /* Index.aiRowLogEst   */
002864                   sizeof(i16)*nCol +            /* Index.aiColumn   */
002865                   sizeof(u8)*nCol);             /* Index.aSortOrder */
002866    p = sqlite3DbMallocZero(db, nByte + nExtra);
002867    if( p ){
002868      char *pExtra = ((char*)p)+ROUND8(sizeof(Index));
002869      p->azColl = (const char**)pExtra; pExtra += ROUND8(sizeof(char*)*nCol);
002870      p->aiRowLogEst = (LogEst*)pExtra; pExtra += sizeof(LogEst)*(nCol+1);
002871      p->aiColumn = (i16*)pExtra;       pExtra += sizeof(i16)*nCol;
002872      p->aSortOrder = (u8*)pExtra;
002873      p->nColumn = nCol;
002874      p->nKeyCol = nCol - 1;
002875      *ppExtra = ((char*)p) + nByte;
002876    }
002877    return p;
002878  }
002879  
002880  /*
002881  ** Create a new index for an SQL table.  pName1.pName2 is the name of the index 
002882  ** and pTblList is the name of the table that is to be indexed.  Both will 
002883  ** be NULL for a primary key or an index that is created to satisfy a
002884  ** UNIQUE constraint.  If pTable and pIndex are NULL, use pParse->pNewTable
002885  ** as the table to be indexed.  pParse->pNewTable is a table that is
002886  ** currently being constructed by a CREATE TABLE statement.
002887  **
002888  ** pList is a list of columns to be indexed.  pList will be NULL if this
002889  ** is a primary key or unique-constraint on the most recent column added
002890  ** to the table currently under construction.  
002891  */
002892  void sqlite3CreateIndex(
002893    Parse *pParse,     /* All information about this parse */
002894    Token *pName1,     /* First part of index name. May be NULL */
002895    Token *pName2,     /* Second part of index name. May be NULL */
002896    SrcList *pTblName, /* Table to index. Use pParse->pNewTable if 0 */
002897    ExprList *pList,   /* A list of columns to be indexed */
002898    int onError,       /* OE_Abort, OE_Ignore, OE_Replace, or OE_None */
002899    Token *pStart,     /* The CREATE token that begins this statement */
002900    Expr *pPIWhere,    /* WHERE clause for partial indices */
002901    int sortOrder,     /* Sort order of primary key when pList==NULL */
002902    int ifNotExist,    /* Omit error if index already exists */
002903    u8 idxType         /* The index type */
002904  ){
002905    Table *pTab = 0;     /* Table to be indexed */
002906    Index *pIndex = 0;   /* The index to be created */
002907    char *zName = 0;     /* Name of the index */
002908    int nName;           /* Number of characters in zName */
002909    int i, j;
002910    DbFixer sFix;        /* For assigning database names to pTable */
002911    int sortOrderMask;   /* 1 to honor DESC in index.  0 to ignore. */
002912    sqlite3 *db = pParse->db;
002913    Db *pDb;             /* The specific table containing the indexed database */
002914    int iDb;             /* Index of the database that is being written */
002915    Token *pName = 0;    /* Unqualified name of the index to create */
002916    struct ExprList_item *pListItem; /* For looping over pList */
002917    int nExtra = 0;                  /* Space allocated for zExtra[] */
002918    int nExtraCol;                   /* Number of extra columns needed */
002919    char *zExtra = 0;                /* Extra space after the Index object */
002920    Index *pPk = 0;      /* PRIMARY KEY index for WITHOUT ROWID tables */
002921  
002922    if( db->mallocFailed || pParse->nErr>0 ){
002923      goto exit_create_index;
002924    }
002925    if( IN_DECLARE_VTAB && idxType!=SQLITE_IDXTYPE_PRIMARYKEY ){
002926      goto exit_create_index;
002927    }
002928    if( SQLITE_OK!=sqlite3ReadSchema(pParse) ){
002929      goto exit_create_index;
002930    }
002931  
002932    /*
002933    ** Find the table that is to be indexed.  Return early if not found.
002934    */
002935    if( pTblName!=0 ){
002936  
002937      /* Use the two-part index name to determine the database 
002938      ** to search for the table. 'Fix' the table name to this db
002939      ** before looking up the table.
002940      */
002941      assert( pName1 && pName2 );
002942      iDb = sqlite3TwoPartName(pParse, pName1, pName2, &pName);
002943      if( iDb<0 ) goto exit_create_index;
002944      assert( pName && pName->z );
002945  
002946  #ifndef SQLITE_OMIT_TEMPDB
002947      /* If the index name was unqualified, check if the table
002948      ** is a temp table. If so, set the database to 1. Do not do this
002949      ** if initialising a database schema.
002950      */
002951      if( !db->init.busy ){
002952        pTab = sqlite3SrcListLookup(pParse, pTblName);
002953        if( pName2->n==0 && pTab && pTab->pSchema==db->aDb[1].pSchema ){
002954          iDb = 1;
002955        }
002956      }
002957  #endif
002958  
002959      sqlite3FixInit(&sFix, pParse, iDb, "index", pName);
002960      if( sqlite3FixSrcList(&sFix, pTblName) ){
002961        /* Because the parser constructs pTblName from a single identifier,
002962        ** sqlite3FixSrcList can never fail. */
002963        assert(0);
002964      }
002965      pTab = sqlite3LocateTableItem(pParse, 0, &pTblName->a[0]);
002966      assert( db->mallocFailed==0 || pTab==0 );
002967      if( pTab==0 ) goto exit_create_index;
002968      if( iDb==1 && db->aDb[iDb].pSchema!=pTab->pSchema ){
002969        sqlite3ErrorMsg(pParse, 
002970             "cannot create a TEMP index on non-TEMP table \"%s\"",
002971             pTab->zName);
002972        goto exit_create_index;
002973      }
002974      if( !HasRowid(pTab) ) pPk = sqlite3PrimaryKeyIndex(pTab);
002975    }else{
002976      assert( pName==0 );
002977      assert( pStart==0 );
002978      pTab = pParse->pNewTable;
002979      if( !pTab ) goto exit_create_index;
002980      iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
002981    }
002982    pDb = &db->aDb[iDb];
002983  
002984    assert( pTab!=0 );
002985    assert( pParse->nErr==0 );
002986    if( sqlite3StrNICmp(pTab->zName, "sqlite_", 7)==0 
002987         && db->init.busy==0
002988  #if SQLITE_USER_AUTHENTICATION
002989         && sqlite3UserAuthTable(pTab->zName)==0
002990  #endif
002991         && sqlite3StrNICmp(&pTab->zName[7],"altertab_",9)!=0 ){
002992      sqlite3ErrorMsg(pParse, "table %s may not be indexed", pTab->zName);
002993      goto exit_create_index;
002994    }
002995  #ifndef SQLITE_OMIT_VIEW
002996    if( pTab->pSelect ){
002997      sqlite3ErrorMsg(pParse, "views may not be indexed");
002998      goto exit_create_index;
002999    }
003000  #endif
003001  #ifndef SQLITE_OMIT_VIRTUALTABLE
003002    if( IsVirtual(pTab) ){
003003      sqlite3ErrorMsg(pParse, "virtual tables may not be indexed");
003004      goto exit_create_index;
003005    }
003006  #endif
003007  
003008    /*
003009    ** Find the name of the index.  Make sure there is not already another
003010    ** index or table with the same name.  
003011    **
003012    ** Exception:  If we are reading the names of permanent indices from the
003013    ** sqlite_master table (because some other process changed the schema) and
003014    ** one of the index names collides with the name of a temporary table or
003015    ** index, then we will continue to process this index.
003016    **
003017    ** If pName==0 it means that we are
003018    ** dealing with a primary key or UNIQUE constraint.  We have to invent our
003019    ** own name.
003020    */
003021    if( pName ){
003022      zName = sqlite3NameFromToken(db, pName);
003023      if( zName==0 ) goto exit_create_index;
003024      assert( pName->z!=0 );
003025      if( SQLITE_OK!=sqlite3CheckObjectName(pParse, zName) ){
003026        goto exit_create_index;
003027      }
003028      if( !db->init.busy ){
003029        if( sqlite3FindTable(db, zName, 0)!=0 ){
003030          sqlite3ErrorMsg(pParse, "there is already a table named %s", zName);
003031          goto exit_create_index;
003032        }
003033      }
003034      if( sqlite3FindIndex(db, zName, pDb->zDbSName)!=0 ){
003035        if( !ifNotExist ){
003036          sqlite3ErrorMsg(pParse, "index %s already exists", zName);
003037        }else{
003038          assert( !db->init.busy );
003039          sqlite3CodeVerifySchema(pParse, iDb);
003040        }
003041        goto exit_create_index;
003042      }
003043    }else{
003044      int n;
003045      Index *pLoop;
003046      for(pLoop=pTab->pIndex, n=1; pLoop; pLoop=pLoop->pNext, n++){}
003047      zName = sqlite3MPrintf(db, "sqlite_autoindex_%s_%d", pTab->zName, n);
003048      if( zName==0 ){
003049        goto exit_create_index;
003050      }
003051  
003052      /* Automatic index names generated from within sqlite3_declare_vtab()
003053      ** must have names that are distinct from normal automatic index names.
003054      ** The following statement converts "sqlite3_autoindex..." into
003055      ** "sqlite3_butoindex..." in order to make the names distinct.
003056      ** The "vtab_err.test" test demonstrates the need of this statement. */
003057      if( IN_DECLARE_VTAB ) zName[7]++;
003058    }
003059  
003060    /* Check for authorization to create an index.
003061    */
003062  #ifndef SQLITE_OMIT_AUTHORIZATION
003063    {
003064      const char *zDb = pDb->zDbSName;
003065      if( sqlite3AuthCheck(pParse, SQLITE_INSERT, SCHEMA_TABLE(iDb), 0, zDb) ){
003066        goto exit_create_index;
003067      }
003068      i = SQLITE_CREATE_INDEX;
003069      if( !OMIT_TEMPDB && iDb==1 ) i = SQLITE_CREATE_TEMP_INDEX;
003070      if( sqlite3AuthCheck(pParse, i, zName, pTab->zName, zDb) ){
003071        goto exit_create_index;
003072      }
003073    }
003074  #endif
003075  
003076    /* If pList==0, it means this routine was called to make a primary
003077    ** key out of the last column added to the table under construction.
003078    ** So create a fake list to simulate this.
003079    */
003080    if( pList==0 ){
003081      Token prevCol;
003082      sqlite3TokenInit(&prevCol, pTab->aCol[pTab->nCol-1].zName);
003083      pList = sqlite3ExprListAppend(pParse, 0,
003084                sqlite3ExprAlloc(db, TK_ID, &prevCol, 0));
003085      if( pList==0 ) goto exit_create_index;
003086      assert( pList->nExpr==1 );
003087      sqlite3ExprListSetSortOrder(pList, sortOrder);
003088    }else{
003089      sqlite3ExprListCheckLength(pParse, pList, "index");
003090    }
003091  
003092    /* Figure out how many bytes of space are required to store explicitly
003093    ** specified collation sequence names.
003094    */
003095    for(i=0; i<pList->nExpr; i++){
003096      Expr *pExpr = pList->a[i].pExpr;
003097      assert( pExpr!=0 );
003098      if( pExpr->op==TK_COLLATE ){
003099        nExtra += (1 + sqlite3Strlen30(pExpr->u.zToken));
003100      }
003101    }
003102  
003103    /* 
003104    ** Allocate the index structure. 
003105    */
003106    nName = sqlite3Strlen30(zName);
003107    nExtraCol = pPk ? pPk->nKeyCol : 1;
003108    pIndex = sqlite3AllocateIndexObject(db, pList->nExpr + nExtraCol,
003109                                        nName + nExtra + 1, &zExtra);
003110    if( db->mallocFailed ){
003111      goto exit_create_index;
003112    }
003113    assert( EIGHT_BYTE_ALIGNMENT(pIndex->aiRowLogEst) );
003114    assert( EIGHT_BYTE_ALIGNMENT(pIndex->azColl) );
003115    pIndex->zName = zExtra;
003116    zExtra += nName + 1;
003117    memcpy(pIndex->zName, zName, nName+1);
003118    pIndex->pTable = pTab;
003119    pIndex->onError = (u8)onError;
003120    pIndex->uniqNotNull = onError!=OE_None;
003121    pIndex->idxType = idxType;
003122    pIndex->pSchema = db->aDb[iDb].pSchema;
003123    pIndex->nKeyCol = pList->nExpr;
003124    if( pPIWhere ){
003125      sqlite3ResolveSelfReference(pParse, pTab, NC_PartIdx, pPIWhere, 0);
003126      pIndex->pPartIdxWhere = pPIWhere;
003127      pPIWhere = 0;
003128    }
003129    assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
003130  
003131    /* Check to see if we should honor DESC requests on index columns
003132    */
003133    if( pDb->pSchema->file_format>=4 ){
003134      sortOrderMask = -1;   /* Honor DESC */
003135    }else{
003136      sortOrderMask = 0;    /* Ignore DESC */
003137    }
003138  
003139    /* Analyze the list of expressions that form the terms of the index and
003140    ** report any errors.  In the common case where the expression is exactly
003141    ** a table column, store that column in aiColumn[].  For general expressions,
003142    ** populate pIndex->aColExpr and store XN_EXPR (-2) in aiColumn[].
003143    **
003144    ** TODO: Issue a warning if two or more columns of the index are identical.
003145    ** TODO: Issue a warning if the table primary key is used as part of the
003146    ** index key.
003147    */
003148    for(i=0, pListItem=pList->a; i<pList->nExpr; i++, pListItem++){
003149      Expr *pCExpr;                  /* The i-th index expression */
003150      int requestedSortOrder;        /* ASC or DESC on the i-th expression */
003151      const char *zColl;             /* Collation sequence name */
003152  
003153      sqlite3StringToId(pListItem->pExpr);
003154      sqlite3ResolveSelfReference(pParse, pTab, NC_IdxExpr, pListItem->pExpr, 0);
003155      if( pParse->nErr ) goto exit_create_index;
003156      pCExpr = sqlite3ExprSkipCollate(pListItem->pExpr);
003157      if( pCExpr->op!=TK_COLUMN ){
003158        if( pTab==pParse->pNewTable ){
003159          sqlite3ErrorMsg(pParse, "expressions prohibited in PRIMARY KEY and "
003160                                  "UNIQUE constraints");
003161          goto exit_create_index;
003162        }
003163        if( pIndex->aColExpr==0 ){
003164          ExprList *pCopy = sqlite3ExprListDup(db, pList, 0);
003165          pIndex->aColExpr = pCopy;
003166          if( !db->mallocFailed ){
003167            assert( pCopy!=0 );
003168            pListItem = &pCopy->a[i];
003169          }
003170        }
003171        j = XN_EXPR;
003172        pIndex->aiColumn[i] = XN_EXPR;
003173        pIndex->uniqNotNull = 0;
003174      }else{
003175        j = pCExpr->iColumn;
003176        assert( j<=0x7fff );
003177        if( j<0 ){
003178          j = pTab->iPKey;
003179        }else if( pTab->aCol[j].notNull==0 ){
003180          pIndex->uniqNotNull = 0;
003181        }
003182        pIndex->aiColumn[i] = (i16)j;
003183      }
003184      zColl = 0;
003185      if( pListItem->pExpr->op==TK_COLLATE ){
003186        int nColl;
003187        zColl = pListItem->pExpr->u.zToken;
003188        nColl = sqlite3Strlen30(zColl) + 1;
003189        assert( nExtra>=nColl );
003190        memcpy(zExtra, zColl, nColl);
003191        zColl = zExtra;
003192        zExtra += nColl;
003193        nExtra -= nColl;
003194      }else if( j>=0 ){
003195        zColl = pTab->aCol[j].zColl;
003196      }
003197      if( !zColl ) zColl = sqlite3StrBINARY;
003198      if( !db->init.busy && !sqlite3LocateCollSeq(pParse, zColl) ){
003199        goto exit_create_index;
003200      }
003201      pIndex->azColl[i] = zColl;
003202      requestedSortOrder = pListItem->sortOrder & sortOrderMask;
003203      pIndex->aSortOrder[i] = (u8)requestedSortOrder;
003204    }
003205  
003206    /* Append the table key to the end of the index.  For WITHOUT ROWID
003207    ** tables (when pPk!=0) this will be the declared PRIMARY KEY.  For
003208    ** normal tables (when pPk==0) this will be the rowid.
003209    */
003210    if( pPk ){
003211      for(j=0; j<pPk->nKeyCol; j++){
003212        int x = pPk->aiColumn[j];
003213        assert( x>=0 );
003214        if( hasColumn(pIndex->aiColumn, pIndex->nKeyCol, x) ){
003215          pIndex->nColumn--; 
003216        }else{
003217          pIndex->aiColumn[i] = x;
003218          pIndex->azColl[i] = pPk->azColl[j];
003219          pIndex->aSortOrder[i] = pPk->aSortOrder[j];
003220          i++;
003221        }
003222      }
003223      assert( i==pIndex->nColumn );
003224    }else{
003225      pIndex->aiColumn[i] = XN_ROWID;
003226      pIndex->azColl[i] = sqlite3StrBINARY;
003227    }
003228    sqlite3DefaultRowEst(pIndex);
003229    if( pParse->pNewTable==0 ) estimateIndexWidth(pIndex);
003230  
003231    /* If this index contains every column of its table, then mark
003232    ** it as a covering index */
003233    assert( HasRowid(pTab) 
003234        || pTab->iPKey<0 || sqlite3ColumnOfIndex(pIndex, pTab->iPKey)>=0 );
003235    if( pTblName!=0 && pIndex->nColumn>=pTab->nCol ){
003236      pIndex->isCovering = 1;
003237      for(j=0; j<pTab->nCol; j++){
003238        if( j==pTab->iPKey ) continue;
003239        if( sqlite3ColumnOfIndex(pIndex,j)>=0 ) continue;
003240        pIndex->isCovering = 0;
003241        break;
003242      }
003243    }
003244  
003245    if( pTab==pParse->pNewTable ){
003246      /* This routine has been called to create an automatic index as a
003247      ** result of a PRIMARY KEY or UNIQUE clause on a column definition, or
003248      ** a PRIMARY KEY or UNIQUE clause following the column definitions.
003249      ** i.e. one of:
003250      **
003251      ** CREATE TABLE t(x PRIMARY KEY, y);
003252      ** CREATE TABLE t(x, y, UNIQUE(x, y));
003253      **
003254      ** Either way, check to see if the table already has such an index. If
003255      ** so, don't bother creating this one. This only applies to
003256      ** automatically created indices. Users can do as they wish with
003257      ** explicit indices.
003258      **
003259      ** Two UNIQUE or PRIMARY KEY constraints are considered equivalent
003260      ** (and thus suppressing the second one) even if they have different
003261      ** sort orders.
003262      **
003263      ** If there are different collating sequences or if the columns of
003264      ** the constraint occur in different orders, then the constraints are
003265      ** considered distinct and both result in separate indices.
003266      */
003267      Index *pIdx;
003268      for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
003269        int k;
003270        assert( IsUniqueIndex(pIdx) );
003271        assert( pIdx->idxType!=SQLITE_IDXTYPE_APPDEF );
003272        assert( IsUniqueIndex(pIndex) );
003273  
003274        if( pIdx->nKeyCol!=pIndex->nKeyCol ) continue;
003275        for(k=0; k<pIdx->nKeyCol; k++){
003276          const char *z1;
003277          const char *z2;
003278          assert( pIdx->aiColumn[k]>=0 );
003279          if( pIdx->aiColumn[k]!=pIndex->aiColumn[k] ) break;
003280          z1 = pIdx->azColl[k];
003281          z2 = pIndex->azColl[k];
003282          if( sqlite3StrICmp(z1, z2) ) break;
003283        }
003284        if( k==pIdx->nKeyCol ){
003285          if( pIdx->onError!=pIndex->onError ){
003286            /* This constraint creates the same index as a previous
003287            ** constraint specified somewhere in the CREATE TABLE statement.
003288            ** However the ON CONFLICT clauses are different. If both this 
003289            ** constraint and the previous equivalent constraint have explicit
003290            ** ON CONFLICT clauses this is an error. Otherwise, use the
003291            ** explicitly specified behavior for the index.
003292            */
003293            if( !(pIdx->onError==OE_Default || pIndex->onError==OE_Default) ){
003294              sqlite3ErrorMsg(pParse, 
003295                  "conflicting ON CONFLICT clauses specified", 0);
003296            }
003297            if( pIdx->onError==OE_Default ){
003298              pIdx->onError = pIndex->onError;
003299            }
003300          }
003301          if( idxType==SQLITE_IDXTYPE_PRIMARYKEY ) pIdx->idxType = idxType;
003302          goto exit_create_index;
003303        }
003304      }
003305    }
003306  
003307    /* Link the new Index structure to its table and to the other
003308    ** in-memory database structures. 
003309    */
003310    assert( pParse->nErr==0 );
003311    if( db->init.busy ){
003312      Index *p;
003313      assert( !IN_DECLARE_VTAB );
003314      assert( sqlite3SchemaMutexHeld(db, 0, pIndex->pSchema) );
003315      p = sqlite3HashInsert(&pIndex->pSchema->idxHash, 
003316                            pIndex->zName, pIndex);
003317      if( p ){
003318        assert( p==pIndex );  /* Malloc must have failed */
003319        sqlite3OomFault(db);
003320        goto exit_create_index;
003321      }
003322      db->flags |= SQLITE_InternChanges;
003323      if( pTblName!=0 ){
003324        pIndex->tnum = db->init.newTnum;
003325      }
003326    }
003327  
003328    /* If this is the initial CREATE INDEX statement (or CREATE TABLE if the
003329    ** index is an implied index for a UNIQUE or PRIMARY KEY constraint) then
003330    ** emit code to allocate the index rootpage on disk and make an entry for
003331    ** the index in the sqlite_master table and populate the index with
003332    ** content.  But, do not do this if we are simply reading the sqlite_master
003333    ** table to parse the schema, or if this index is the PRIMARY KEY index
003334    ** of a WITHOUT ROWID table.
003335    **
003336    ** If pTblName==0 it means this index is generated as an implied PRIMARY KEY
003337    ** or UNIQUE index in a CREATE TABLE statement.  Since the table
003338    ** has just been created, it contains no data and the index initialization
003339    ** step can be skipped.
003340    */
003341    else if( HasRowid(pTab) || pTblName!=0 ){
003342      Vdbe *v;
003343      char *zStmt;
003344      int iMem = ++pParse->nMem;
003345  
003346      v = sqlite3GetVdbe(pParse);
003347      if( v==0 ) goto exit_create_index;
003348  
003349      sqlite3BeginWriteOperation(pParse, 1, iDb);
003350  
003351      /* Create the rootpage for the index using CreateIndex. But before
003352      ** doing so, code a Noop instruction and store its address in 
003353      ** Index.tnum. This is required in case this index is actually a 
003354      ** PRIMARY KEY and the table is actually a WITHOUT ROWID table. In 
003355      ** that case the convertToWithoutRowidTable() routine will replace
003356      ** the Noop with a Goto to jump over the VDBE code generated below. */
003357      pIndex->tnum = sqlite3VdbeAddOp0(v, OP_Noop);
003358      sqlite3VdbeAddOp2(v, OP_CreateIndex, iDb, iMem);
003359  
003360      /* Gather the complete text of the CREATE INDEX statement into
003361      ** the zStmt variable
003362      */
003363      if( pStart ){
003364        int n = (int)(pParse->sLastToken.z - pName->z) + pParse->sLastToken.n;
003365        if( pName->z[n-1]==';' ) n--;
003366        /* A named index with an explicit CREATE INDEX statement */
003367        zStmt = sqlite3MPrintf(db, "CREATE%s INDEX %.*s",
003368          onError==OE_None ? "" : " UNIQUE", n, pName->z);
003369      }else{
003370        /* An automatic index created by a PRIMARY KEY or UNIQUE constraint */
003371        /* zStmt = sqlite3MPrintf(""); */
003372        zStmt = 0;
003373      }
003374  
003375      /* Add an entry in sqlite_master for this index
003376      */
003377      sqlite3NestedParse(pParse, 
003378          "INSERT INTO %Q.%s VALUES('index',%Q,%Q,#%d,%Q);",
003379          db->aDb[iDb].zDbSName, MASTER_NAME,
003380          pIndex->zName,
003381          pTab->zName,
003382          iMem,
003383          zStmt
003384      );
003385      sqlite3DbFree(db, zStmt);
003386  
003387      /* Fill the index with data and reparse the schema. Code an OP_Expire
003388      ** to invalidate all pre-compiled statements.
003389      */
003390      if( pTblName ){
003391        sqlite3RefillIndex(pParse, pIndex, iMem);
003392        sqlite3ChangeCookie(pParse, iDb);
003393        sqlite3VdbeAddParseSchemaOp(v, iDb,
003394           sqlite3MPrintf(db, "name='%q' AND type='index'", pIndex->zName));
003395        sqlite3VdbeAddOp0(v, OP_Expire);
003396      }
003397  
003398      sqlite3VdbeJumpHere(v, pIndex->tnum);
003399    }
003400  
003401    /* When adding an index to the list of indices for a table, make
003402    ** sure all indices labeled OE_Replace come after all those labeled
003403    ** OE_Ignore.  This is necessary for the correct constraint check
003404    ** processing (in sqlite3GenerateConstraintChecks()) as part of
003405    ** UPDATE and INSERT statements.  
003406    */
003407    if( db->init.busy || pTblName==0 ){
003408      if( onError!=OE_Replace || pTab->pIndex==0
003409           || pTab->pIndex->onError==OE_Replace){
003410        pIndex->pNext = pTab->pIndex;
003411        pTab->pIndex = pIndex;
003412      }else{
003413        Index *pOther = pTab->pIndex;
003414        while( pOther->pNext && pOther->pNext->onError!=OE_Replace ){
003415          pOther = pOther->pNext;
003416        }
003417        pIndex->pNext = pOther->pNext;
003418        pOther->pNext = pIndex;
003419      }
003420      pIndex = 0;
003421    }
003422  
003423    /* Clean up before exiting */
003424  exit_create_index:
003425    if( pIndex ) freeIndex(db, pIndex);
003426    sqlite3ExprDelete(db, pPIWhere);
003427    sqlite3ExprListDelete(db, pList);
003428    sqlite3SrcListDelete(db, pTblName);
003429    sqlite3DbFree(db, zName);
003430  }
003431  
003432  /*
003433  ** Fill the Index.aiRowEst[] array with default information - information
003434  ** to be used when we have not run the ANALYZE command.
003435  **
003436  ** aiRowEst[0] is supposed to contain the number of elements in the index.
003437  ** Since we do not know, guess 1 million.  aiRowEst[1] is an estimate of the
003438  ** number of rows in the table that match any particular value of the
003439  ** first column of the index.  aiRowEst[2] is an estimate of the number
003440  ** of rows that match any particular combination of the first 2 columns
003441  ** of the index.  And so forth.  It must always be the case that
003442  *
003443  **           aiRowEst[N]<=aiRowEst[N-1]
003444  **           aiRowEst[N]>=1
003445  **
003446  ** Apart from that, we have little to go on besides intuition as to
003447  ** how aiRowEst[] should be initialized.  The numbers generated here
003448  ** are based on typical values found in actual indices.
003449  */
003450  void sqlite3DefaultRowEst(Index *pIdx){
003451    /*                10,  9,  8,  7,  6 */
003452    LogEst aVal[] = { 33, 32, 30, 28, 26 };
003453    LogEst *a = pIdx->aiRowLogEst;
003454    int nCopy = MIN(ArraySize(aVal), pIdx->nKeyCol);
003455    int i;
003456  
003457    /* Set the first entry (number of rows in the index) to the estimated 
003458    ** number of rows in the table, or half the number of rows in the table
003459    ** for a partial index.   But do not let the estimate drop below 10. */
003460    a[0] = pIdx->pTable->nRowLogEst;
003461    if( pIdx->pPartIdxWhere!=0 ) a[0] -= 10;  assert( 10==sqlite3LogEst(2) );
003462    if( a[0]<33 ) a[0] = 33;                  assert( 33==sqlite3LogEst(10) );
003463  
003464    /* Estimate that a[1] is 10, a[2] is 9, a[3] is 8, a[4] is 7, a[5] is
003465    ** 6 and each subsequent value (if any) is 5.  */
003466    memcpy(&a[1], aVal, nCopy*sizeof(LogEst));
003467    for(i=nCopy+1; i<=pIdx->nKeyCol; i++){
003468      a[i] = 23;                    assert( 23==sqlite3LogEst(5) );
003469    }
003470  
003471    assert( 0==sqlite3LogEst(1) );
003472    if( IsUniqueIndex(pIdx) ) a[pIdx->nKeyCol] = 0;
003473  }
003474  
003475  /*
003476  ** This routine will drop an existing named index.  This routine
003477  ** implements the DROP INDEX statement.
003478  */
003479  void sqlite3DropIndex(Parse *pParse, SrcList *pName, int ifExists){
003480    Index *pIndex;
003481    Vdbe *v;
003482    sqlite3 *db = pParse->db;
003483    int iDb;
003484  
003485    assert( pParse->nErr==0 );   /* Never called with prior errors */
003486    if( db->mallocFailed ){
003487      goto exit_drop_index;
003488    }
003489    assert( pName->nSrc==1 );
003490    if( SQLITE_OK!=sqlite3ReadSchema(pParse) ){
003491      goto exit_drop_index;
003492    }
003493    pIndex = sqlite3FindIndex(db, pName->a[0].zName, pName->a[0].zDatabase);
003494    if( pIndex==0 ){
003495      if( !ifExists ){
003496        sqlite3ErrorMsg(pParse, "no such index: %S", pName, 0);
003497      }else{
003498        sqlite3CodeVerifyNamedSchema(pParse, pName->a[0].zDatabase);
003499      }
003500      pParse->checkSchema = 1;
003501      goto exit_drop_index;
003502    }
003503    if( pIndex->idxType!=SQLITE_IDXTYPE_APPDEF ){
003504      sqlite3ErrorMsg(pParse, "index associated with UNIQUE "
003505        "or PRIMARY KEY constraint cannot be dropped", 0);
003506      goto exit_drop_index;
003507    }
003508    iDb = sqlite3SchemaToIndex(db, pIndex->pSchema);
003509  #ifndef SQLITE_OMIT_AUTHORIZATION
003510    {
003511      int code = SQLITE_DROP_INDEX;
003512      Table *pTab = pIndex->pTable;
003513      const char *zDb = db->aDb[iDb].zDbSName;
003514      const char *zTab = SCHEMA_TABLE(iDb);
003515      if( sqlite3AuthCheck(pParse, SQLITE_DELETE, zTab, 0, zDb) ){
003516        goto exit_drop_index;
003517      }
003518      if( !OMIT_TEMPDB && iDb ) code = SQLITE_DROP_TEMP_INDEX;
003519      if( sqlite3AuthCheck(pParse, code, pIndex->zName, pTab->zName, zDb) ){
003520        goto exit_drop_index;
003521      }
003522    }
003523  #endif
003524  
003525    /* Generate code to remove the index and from the master table */
003526    v = sqlite3GetVdbe(pParse);
003527    if( v ){
003528      sqlite3BeginWriteOperation(pParse, 1, iDb);
003529      sqlite3NestedParse(pParse,
003530         "DELETE FROM %Q.%s WHERE name=%Q AND type='index'",
003531         db->aDb[iDb].zDbSName, MASTER_NAME, pIndex->zName
003532      );
003533      sqlite3ClearStatTables(pParse, iDb, "idx", pIndex->zName);
003534      sqlite3ChangeCookie(pParse, iDb);
003535      destroyRootPage(pParse, pIndex->tnum, iDb);
003536      sqlite3VdbeAddOp4(v, OP_DropIndex, iDb, 0, 0, pIndex->zName, 0);
003537    }
003538  
003539  exit_drop_index:
003540    sqlite3SrcListDelete(db, pName);
003541  }
003542  
003543  /*
003544  ** pArray is a pointer to an array of objects. Each object in the
003545  ** array is szEntry bytes in size. This routine uses sqlite3DbRealloc()
003546  ** to extend the array so that there is space for a new object at the end.
003547  **
003548  ** When this function is called, *pnEntry contains the current size of
003549  ** the array (in entries - so the allocation is ((*pnEntry) * szEntry) bytes
003550  ** in total).
003551  **
003552  ** If the realloc() is successful (i.e. if no OOM condition occurs), the
003553  ** space allocated for the new object is zeroed, *pnEntry updated to
003554  ** reflect the new size of the array and a pointer to the new allocation
003555  ** returned. *pIdx is set to the index of the new array entry in this case.
003556  **
003557  ** Otherwise, if the realloc() fails, *pIdx is set to -1, *pnEntry remains
003558  ** unchanged and a copy of pArray returned.
003559  */
003560  void *sqlite3ArrayAllocate(
003561    sqlite3 *db,      /* Connection to notify of malloc failures */
003562    void *pArray,     /* Array of objects.  Might be reallocated */
003563    int szEntry,      /* Size of each object in the array */
003564    int *pnEntry,     /* Number of objects currently in use */
003565    int *pIdx         /* Write the index of a new slot here */
003566  ){
003567    char *z;
003568    int n = *pnEntry;
003569    if( (n & (n-1))==0 ){
003570      int sz = (n==0) ? 1 : 2*n;
003571      void *pNew = sqlite3DbRealloc(db, pArray, sz*szEntry);
003572      if( pNew==0 ){
003573        *pIdx = -1;
003574        return pArray;
003575      }
003576      pArray = pNew;
003577    }
003578    z = (char*)pArray;
003579    memset(&z[n * szEntry], 0, szEntry);
003580    *pIdx = n;
003581    ++*pnEntry;
003582    return pArray;
003583  }
003584  
003585  /*
003586  ** Append a new element to the given IdList.  Create a new IdList if
003587  ** need be.
003588  **
003589  ** A new IdList is returned, or NULL if malloc() fails.
003590  */
003591  IdList *sqlite3IdListAppend(sqlite3 *db, IdList *pList, Token *pToken){
003592    int i;
003593    if( pList==0 ){
003594      pList = sqlite3DbMallocZero(db, sizeof(IdList) );
003595      if( pList==0 ) return 0;
003596    }
003597    pList->a = sqlite3ArrayAllocate(
003598        db,
003599        pList->a,
003600        sizeof(pList->a[0]),
003601        &pList->nId,
003602        &i
003603    );
003604    if( i<0 ){
003605      sqlite3IdListDelete(db, pList);
003606      return 0;
003607    }
003608    pList->a[i].zName = sqlite3NameFromToken(db, pToken);
003609    return pList;
003610  }
003611  
003612  /*
003613  ** Delete an IdList.
003614  */
003615  void sqlite3IdListDelete(sqlite3 *db, IdList *pList){
003616    int i;
003617    if( pList==0 ) return;
003618    for(i=0; i<pList->nId; i++){
003619      sqlite3DbFree(db, pList->a[i].zName);
003620    }
003621    sqlite3DbFree(db, pList->a);
003622    sqlite3DbFree(db, pList);
003623  }
003624  
003625  /*
003626  ** Return the index in pList of the identifier named zId.  Return -1
003627  ** if not found.
003628  */
003629  int sqlite3IdListIndex(IdList *pList, const char *zName){
003630    int i;
003631    if( pList==0 ) return -1;
003632    for(i=0; i<pList->nId; i++){
003633      if( sqlite3StrICmp(pList->a[i].zName, zName)==0 ) return i;
003634    }
003635    return -1;
003636  }
003637  
003638  /*
003639  ** Expand the space allocated for the given SrcList object by
003640  ** creating nExtra new slots beginning at iStart.  iStart is zero based.
003641  ** New slots are zeroed.
003642  **
003643  ** For example, suppose a SrcList initially contains two entries: A,B.
003644  ** To append 3 new entries onto the end, do this:
003645  **
003646  **    sqlite3SrcListEnlarge(db, pSrclist, 3, 2);
003647  **
003648  ** After the call above it would contain:  A, B, nil, nil, nil.
003649  ** If the iStart argument had been 1 instead of 2, then the result
003650  ** would have been:  A, nil, nil, nil, B.  To prepend the new slots,
003651  ** the iStart value would be 0.  The result then would
003652  ** be: nil, nil, nil, A, B.
003653  **
003654  ** If a memory allocation fails the SrcList is unchanged.  The
003655  ** db->mallocFailed flag will be set to true.
003656  */
003657  SrcList *sqlite3SrcListEnlarge(
003658    sqlite3 *db,       /* Database connection to notify of OOM errors */
003659    SrcList *pSrc,     /* The SrcList to be enlarged */
003660    int nExtra,        /* Number of new slots to add to pSrc->a[] */
003661    int iStart         /* Index in pSrc->a[] of first new slot */
003662  ){
003663    int i;
003664  
003665    /* Sanity checking on calling parameters */
003666    assert( iStart>=0 );
003667    assert( nExtra>=1 );
003668    assert( pSrc!=0 );
003669    assert( iStart<=pSrc->nSrc );
003670  
003671    /* Allocate additional space if needed */
003672    if( (u32)pSrc->nSrc+nExtra>pSrc->nAlloc ){
003673      SrcList *pNew;
003674      int nAlloc = pSrc->nSrc*2+nExtra;
003675      int nGot;
003676      pNew = sqlite3DbRealloc(db, pSrc,
003677                 sizeof(*pSrc) + (nAlloc-1)*sizeof(pSrc->a[0]) );
003678      if( pNew==0 ){
003679        assert( db->mallocFailed );
003680        return pSrc;
003681      }
003682      pSrc = pNew;
003683      nGot = (sqlite3DbMallocSize(db, pNew) - sizeof(*pSrc))/sizeof(pSrc->a[0])+1;
003684      pSrc->nAlloc = nGot;
003685    }
003686  
003687    /* Move existing slots that come after the newly inserted slots
003688    ** out of the way */
003689    for(i=pSrc->nSrc-1; i>=iStart; i--){
003690      pSrc->a[i+nExtra] = pSrc->a[i];
003691    }
003692    pSrc->nSrc += nExtra;
003693  
003694    /* Zero the newly allocated slots */
003695    memset(&pSrc->a[iStart], 0, sizeof(pSrc->a[0])*nExtra);
003696    for(i=iStart; i<iStart+nExtra; i++){
003697      pSrc->a[i].iCursor = -1;
003698    }
003699  
003700    /* Return a pointer to the enlarged SrcList */
003701    return pSrc;
003702  }
003703  
003704  
003705  /*
003706  ** Append a new table name to the given SrcList.  Create a new SrcList if
003707  ** need be.  A new entry is created in the SrcList even if pTable is NULL.
003708  **
003709  ** A SrcList is returned, or NULL if there is an OOM error.  The returned
003710  ** SrcList might be the same as the SrcList that was input or it might be
003711  ** a new one.  If an OOM error does occurs, then the prior value of pList
003712  ** that is input to this routine is automatically freed.
003713  **
003714  ** If pDatabase is not null, it means that the table has an optional
003715  ** database name prefix.  Like this:  "database.table".  The pDatabase
003716  ** points to the table name and the pTable points to the database name.
003717  ** The SrcList.a[].zName field is filled with the table name which might
003718  ** come from pTable (if pDatabase is NULL) or from pDatabase.  
003719  ** SrcList.a[].zDatabase is filled with the database name from pTable,
003720  ** or with NULL if no database is specified.
003721  **
003722  ** In other words, if call like this:
003723  **
003724  **         sqlite3SrcListAppend(D,A,B,0);
003725  **
003726  ** Then B is a table name and the database name is unspecified.  If called
003727  ** like this:
003728  **
003729  **         sqlite3SrcListAppend(D,A,B,C);
003730  **
003731  ** Then C is the table name and B is the database name.  If C is defined
003732  ** then so is B.  In other words, we never have a case where:
003733  **
003734  **         sqlite3SrcListAppend(D,A,0,C);
003735  **
003736  ** Both pTable and pDatabase are assumed to be quoted.  They are dequoted
003737  ** before being added to the SrcList.
003738  */
003739  SrcList *sqlite3SrcListAppend(
003740    sqlite3 *db,        /* Connection to notify of malloc failures */
003741    SrcList *pList,     /* Append to this SrcList. NULL creates a new SrcList */
003742    Token *pTable,      /* Table to append */
003743    Token *pDatabase    /* Database of the table */
003744  ){
003745    struct SrcList_item *pItem;
003746    assert( pDatabase==0 || pTable!=0 );  /* Cannot have C without B */
003747    assert( db!=0 );
003748    if( pList==0 ){
003749      pList = sqlite3DbMallocRawNN(db, sizeof(SrcList) );
003750      if( pList==0 ) return 0;
003751      pList->nAlloc = 1;
003752      pList->nSrc = 1;
003753      memset(&pList->a[0], 0, sizeof(pList->a[0]));
003754      pList->a[0].iCursor = -1;
003755    }else{
003756      pList = sqlite3SrcListEnlarge(db, pList, 1, pList->nSrc);
003757    }
003758    if( db->mallocFailed ){
003759      sqlite3SrcListDelete(db, pList);
003760      return 0;
003761    }
003762    pItem = &pList->a[pList->nSrc-1];
003763    if( pDatabase && pDatabase->z==0 ){
003764      pDatabase = 0;
003765    }
003766    if( pDatabase ){
003767      Token *pTemp = pDatabase;
003768      pDatabase = pTable;
003769      pTable = pTemp;
003770    }
003771    pItem->zName = sqlite3NameFromToken(db, pTable);
003772    pItem->zDatabase = sqlite3NameFromToken(db, pDatabase);
003773    return pList;
003774  }
003775  
003776  /*
003777  ** Assign VdbeCursor index numbers to all tables in a SrcList
003778  */
003779  void sqlite3SrcListAssignCursors(Parse *pParse, SrcList *pList){
003780    int i;
003781    struct SrcList_item *pItem;
003782    assert(pList || pParse->db->mallocFailed );
003783    if( pList ){
003784      for(i=0, pItem=pList->a; i<pList->nSrc; i++, pItem++){
003785        if( pItem->iCursor>=0 ) break;
003786        pItem->iCursor = pParse->nTab++;
003787        if( pItem->pSelect ){
003788          sqlite3SrcListAssignCursors(pParse, pItem->pSelect->pSrc);
003789        }
003790      }
003791    }
003792  }
003793  
003794  /*
003795  ** Delete an entire SrcList including all its substructure.
003796  */
003797  void sqlite3SrcListDelete(sqlite3 *db, SrcList *pList){
003798    int i;
003799    struct SrcList_item *pItem;
003800    if( pList==0 ) return;
003801    for(pItem=pList->a, i=0; i<pList->nSrc; i++, pItem++){
003802      sqlite3DbFree(db, pItem->zDatabase);
003803      sqlite3DbFree(db, pItem->zName);
003804      sqlite3DbFree(db, pItem->zAlias);
003805      if( pItem->fg.isIndexedBy ) sqlite3DbFree(db, pItem->u1.zIndexedBy);
003806      if( pItem->fg.isTabFunc ) sqlite3ExprListDelete(db, pItem->u1.pFuncArg);
003807      sqlite3DeleteTable(db, pItem->pTab);
003808      sqlite3SelectDelete(db, pItem->pSelect);
003809      sqlite3ExprDelete(db, pItem->pOn);
003810      sqlite3IdListDelete(db, pItem->pUsing);
003811    }
003812    sqlite3DbFree(db, pList);
003813  }
003814  
003815  /*
003816  ** This routine is called by the parser to add a new term to the
003817  ** end of a growing FROM clause.  The "p" parameter is the part of
003818  ** the FROM clause that has already been constructed.  "p" is NULL
003819  ** if this is the first term of the FROM clause.  pTable and pDatabase
003820  ** are the name of the table and database named in the FROM clause term.
003821  ** pDatabase is NULL if the database name qualifier is missing - the
003822  ** usual case.  If the term has an alias, then pAlias points to the
003823  ** alias token.  If the term is a subquery, then pSubquery is the
003824  ** SELECT statement that the subquery encodes.  The pTable and
003825  ** pDatabase parameters are NULL for subqueries.  The pOn and pUsing
003826  ** parameters are the content of the ON and USING clauses.
003827  **
003828  ** Return a new SrcList which encodes is the FROM with the new
003829  ** term added.
003830  */
003831  SrcList *sqlite3SrcListAppendFromTerm(
003832    Parse *pParse,          /* Parsing context */
003833    SrcList *p,             /* The left part of the FROM clause already seen */
003834    Token *pTable,          /* Name of the table to add to the FROM clause */
003835    Token *pDatabase,       /* Name of the database containing pTable */
003836    Token *pAlias,          /* The right-hand side of the AS subexpression */
003837    Select *pSubquery,      /* A subquery used in place of a table name */
003838    Expr *pOn,              /* The ON clause of a join */
003839    IdList *pUsing          /* The USING clause of a join */
003840  ){
003841    struct SrcList_item *pItem;
003842    sqlite3 *db = pParse->db;
003843    if( !p && (pOn || pUsing) ){
003844      sqlite3ErrorMsg(pParse, "a JOIN clause is required before %s", 
003845        (pOn ? "ON" : "USING")
003846      );
003847      goto append_from_error;
003848    }
003849    p = sqlite3SrcListAppend(db, p, pTable, pDatabase);
003850    if( p==0 || NEVER(p->nSrc==0) ){
003851      goto append_from_error;
003852    }
003853    pItem = &p->a[p->nSrc-1];
003854    assert( pAlias!=0 );
003855    if( pAlias->n ){
003856      pItem->zAlias = sqlite3NameFromToken(db, pAlias);
003857    }
003858    pItem->pSelect = pSubquery;
003859    pItem->pOn = pOn;
003860    pItem->pUsing = pUsing;
003861    return p;
003862  
003863   append_from_error:
003864    assert( p==0 );
003865    sqlite3ExprDelete(db, pOn);
003866    sqlite3IdListDelete(db, pUsing);
003867    sqlite3SelectDelete(db, pSubquery);
003868    return 0;
003869  }
003870  
003871  /*
003872  ** Add an INDEXED BY or NOT INDEXED clause to the most recently added 
003873  ** element of the source-list passed as the second argument.
003874  */
003875  void sqlite3SrcListIndexedBy(Parse *pParse, SrcList *p, Token *pIndexedBy){
003876    assert( pIndexedBy!=0 );
003877    if( p && ALWAYS(p->nSrc>0) ){
003878      struct SrcList_item *pItem = &p->a[p->nSrc-1];
003879      assert( pItem->fg.notIndexed==0 );
003880      assert( pItem->fg.isIndexedBy==0 );
003881      assert( pItem->fg.isTabFunc==0 );
003882      if( pIndexedBy->n==1 && !pIndexedBy->z ){
003883        /* A "NOT INDEXED" clause was supplied. See parse.y 
003884        ** construct "indexed_opt" for details. */
003885        pItem->fg.notIndexed = 1;
003886      }else{
003887        pItem->u1.zIndexedBy = sqlite3NameFromToken(pParse->db, pIndexedBy);
003888        pItem->fg.isIndexedBy = (pItem->u1.zIndexedBy!=0);
003889      }
003890    }
003891  }
003892  
003893  /*
003894  ** Add the list of function arguments to the SrcList entry for a
003895  ** table-valued-function.
003896  */
003897  void sqlite3SrcListFuncArgs(Parse *pParse, SrcList *p, ExprList *pList){
003898    if( p ){
003899      struct SrcList_item *pItem = &p->a[p->nSrc-1];
003900      assert( pItem->fg.notIndexed==0 );
003901      assert( pItem->fg.isIndexedBy==0 );
003902      assert( pItem->fg.isTabFunc==0 );
003903      pItem->u1.pFuncArg = pList;
003904      pItem->fg.isTabFunc = 1;
003905    }else{
003906      sqlite3ExprListDelete(pParse->db, pList);
003907    }
003908  }
003909  
003910  /*
003911  ** When building up a FROM clause in the parser, the join operator
003912  ** is initially attached to the left operand.  But the code generator
003913  ** expects the join operator to be on the right operand.  This routine
003914  ** Shifts all join operators from left to right for an entire FROM
003915  ** clause.
003916  **
003917  ** Example: Suppose the join is like this:
003918  **
003919  **           A natural cross join B
003920  **
003921  ** The operator is "natural cross join".  The A and B operands are stored
003922  ** in p->a[0] and p->a[1], respectively.  The parser initially stores the
003923  ** operator with A.  This routine shifts that operator over to B.
003924  */
003925  void sqlite3SrcListShiftJoinType(SrcList *p){
003926    if( p ){
003927      int i;
003928      for(i=p->nSrc-1; i>0; i--){
003929        p->a[i].fg.jointype = p->a[i-1].fg.jointype;
003930      }
003931      p->a[0].fg.jointype = 0;
003932    }
003933  }
003934  
003935  /*
003936  ** Generate VDBE code for a BEGIN statement.
003937  */
003938  void sqlite3BeginTransaction(Parse *pParse, int type){
003939    sqlite3 *db;
003940    Vdbe *v;
003941    int i;
003942  
003943    assert( pParse!=0 );
003944    db = pParse->db;
003945    assert( db!=0 );
003946    if( sqlite3AuthCheck(pParse, SQLITE_TRANSACTION, "BEGIN", 0, 0) ){
003947      return;
003948    }
003949    v = sqlite3GetVdbe(pParse);
003950    if( !v ) return;
003951    if( type!=TK_DEFERRED ){
003952      for(i=0; i<db->nDb; i++){
003953        sqlite3VdbeAddOp2(v, OP_Transaction, i, (type==TK_EXCLUSIVE)+1);
003954        sqlite3VdbeUsesBtree(v, i);
003955      }
003956    }
003957    sqlite3VdbeAddOp0(v, OP_AutoCommit);
003958  }
003959  
003960  /*
003961  ** Generate VDBE code for a COMMIT statement.
003962  */
003963  void sqlite3CommitTransaction(Parse *pParse){
003964    Vdbe *v;
003965  
003966    assert( pParse!=0 );
003967    assert( pParse->db!=0 );
003968    if( sqlite3AuthCheck(pParse, SQLITE_TRANSACTION, "COMMIT", 0, 0) ){
003969      return;
003970    }
003971    v = sqlite3GetVdbe(pParse);
003972    if( v ){
003973      sqlite3VdbeAddOp1(v, OP_AutoCommit, 1);
003974    }
003975  }
003976  
003977  /*
003978  ** Generate VDBE code for a ROLLBACK statement.
003979  */
003980  void sqlite3RollbackTransaction(Parse *pParse){
003981    Vdbe *v;
003982  
003983    assert( pParse!=0 );
003984    assert( pParse->db!=0 );
003985    if( sqlite3AuthCheck(pParse, SQLITE_TRANSACTION, "ROLLBACK", 0, 0) ){
003986      return;
003987    }
003988    v = sqlite3GetVdbe(pParse);
003989    if( v ){
003990      sqlite3VdbeAddOp2(v, OP_AutoCommit, 1, 1);
003991    }
003992  }
003993  
003994  /*
003995  ** This function is called by the parser when it parses a command to create,
003996  ** release or rollback an SQL savepoint. 
003997  */
003998  void sqlite3Savepoint(Parse *pParse, int op, Token *pName){
003999    char *zName = sqlite3NameFromToken(pParse->db, pName);
004000    if( zName ){
004001      Vdbe *v = sqlite3GetVdbe(pParse);
004002  #ifndef SQLITE_OMIT_AUTHORIZATION
004003      static const char * const az[] = { "BEGIN", "RELEASE", "ROLLBACK" };
004004      assert( !SAVEPOINT_BEGIN && SAVEPOINT_RELEASE==1 && SAVEPOINT_ROLLBACK==2 );
004005  #endif
004006      if( !v || sqlite3AuthCheck(pParse, SQLITE_SAVEPOINT, az[op], zName, 0) ){
004007        sqlite3DbFree(pParse->db, zName);
004008        return;
004009      }
004010      sqlite3VdbeAddOp4(v, OP_Savepoint, op, 0, 0, zName, P4_DYNAMIC);
004011    }
004012  }
004013  
004014  /*
004015  ** Make sure the TEMP database is open and available for use.  Return
004016  ** the number of errors.  Leave any error messages in the pParse structure.
004017  */
004018  int sqlite3OpenTempDatabase(Parse *pParse){
004019    sqlite3 *db = pParse->db;
004020    if( db->aDb[1].pBt==0 && !pParse->explain ){
004021      int rc;
004022      Btree *pBt;
004023      static const int flags = 
004024            SQLITE_OPEN_READWRITE |
004025            SQLITE_OPEN_CREATE |
004026            SQLITE_OPEN_EXCLUSIVE |
004027            SQLITE_OPEN_DELETEONCLOSE |
004028            SQLITE_OPEN_TEMP_DB;
004029  
004030      rc = sqlite3BtreeOpen(db->pVfs, 0, db, &pBt, 0, flags);
004031      if( rc!=SQLITE_OK ){
004032        sqlite3ErrorMsg(pParse, "unable to open a temporary database "
004033          "file for storing temporary tables");
004034        pParse->rc = rc;
004035        return 1;
004036      }
004037      db->aDb[1].pBt = pBt;
004038      assert( db->aDb[1].pSchema );
004039      if( SQLITE_NOMEM==sqlite3BtreeSetPageSize(pBt, db->nextPagesize, -1, 0) ){
004040        sqlite3OomFault(db);
004041        return 1;
004042      }
004043    }
004044    return 0;
004045  }
004046  
004047  /*
004048  ** Record the fact that the schema cookie will need to be verified
004049  ** for database iDb.  The code to actually verify the schema cookie
004050  ** will occur at the end of the top-level VDBE and will be generated
004051  ** later, by sqlite3FinishCoding().
004052  */
004053  void sqlite3CodeVerifySchema(Parse *pParse, int iDb){
004054    Parse *pToplevel = sqlite3ParseToplevel(pParse);
004055  
004056    assert( iDb>=0 && iDb<pParse->db->nDb );
004057    assert( pParse->db->aDb[iDb].pBt!=0 || iDb==1 );
004058    assert( iDb<SQLITE_MAX_ATTACHED+2 );
004059    assert( sqlite3SchemaMutexHeld(pParse->db, iDb, 0) );
004060    if( DbMaskTest(pToplevel->cookieMask, iDb)==0 ){
004061      DbMaskSet(pToplevel->cookieMask, iDb);
004062      if( !OMIT_TEMPDB && iDb==1 ){
004063        sqlite3OpenTempDatabase(pToplevel);
004064      }
004065    }
004066  }
004067  
004068  /*
004069  ** If argument zDb is NULL, then call sqlite3CodeVerifySchema() for each 
004070  ** attached database. Otherwise, invoke it for the database named zDb only.
004071  */
004072  void sqlite3CodeVerifyNamedSchema(Parse *pParse, const char *zDb){
004073    sqlite3 *db = pParse->db;
004074    int i;
004075    for(i=0; i<db->nDb; i++){
004076      Db *pDb = &db->aDb[i];
004077      if( pDb->pBt && (!zDb || 0==sqlite3StrICmp(zDb, pDb->zDbSName)) ){
004078        sqlite3CodeVerifySchema(pParse, i);
004079      }
004080    }
004081  }
004082  
004083  /*
004084  ** Generate VDBE code that prepares for doing an operation that
004085  ** might change the database.
004086  **
004087  ** This routine starts a new transaction if we are not already within
004088  ** a transaction.  If we are already within a transaction, then a checkpoint
004089  ** is set if the setStatement parameter is true.  A checkpoint should
004090  ** be set for operations that might fail (due to a constraint) part of
004091  ** the way through and which will need to undo some writes without having to
004092  ** rollback the whole transaction.  For operations where all constraints
004093  ** can be checked before any changes are made to the database, it is never
004094  ** necessary to undo a write and the checkpoint should not be set.
004095  */
004096  void sqlite3BeginWriteOperation(Parse *pParse, int setStatement, int iDb){
004097    Parse *pToplevel = sqlite3ParseToplevel(pParse);
004098    sqlite3CodeVerifySchema(pParse, iDb);
004099    DbMaskSet(pToplevel->writeMask, iDb);
004100    pToplevel->isMultiWrite |= setStatement;
004101  }
004102  
004103  /*
004104  ** Indicate that the statement currently under construction might write
004105  ** more than one entry (example: deleting one row then inserting another,
004106  ** inserting multiple rows in a table, or inserting a row and index entries.)
004107  ** If an abort occurs after some of these writes have completed, then it will
004108  ** be necessary to undo the completed writes.
004109  */
004110  void sqlite3MultiWrite(Parse *pParse){
004111    Parse *pToplevel = sqlite3ParseToplevel(pParse);
004112    pToplevel->isMultiWrite = 1;
004113  }
004114  
004115  /* 
004116  ** The code generator calls this routine if is discovers that it is
004117  ** possible to abort a statement prior to completion.  In order to 
004118  ** perform this abort without corrupting the database, we need to make
004119  ** sure that the statement is protected by a statement transaction.
004120  **
004121  ** Technically, we only need to set the mayAbort flag if the
004122  ** isMultiWrite flag was previously set.  There is a time dependency
004123  ** such that the abort must occur after the multiwrite.  This makes
004124  ** some statements involving the REPLACE conflict resolution algorithm
004125  ** go a little faster.  But taking advantage of this time dependency
004126  ** makes it more difficult to prove that the code is correct (in 
004127  ** particular, it prevents us from writing an effective
004128  ** implementation of sqlite3AssertMayAbort()) and so we have chosen
004129  ** to take the safe route and skip the optimization.
004130  */
004131  void sqlite3MayAbort(Parse *pParse){
004132    Parse *pToplevel = sqlite3ParseToplevel(pParse);
004133    pToplevel->mayAbort = 1;
004134  }
004135  
004136  /*
004137  ** Code an OP_Halt that causes the vdbe to return an SQLITE_CONSTRAINT
004138  ** error. The onError parameter determines which (if any) of the statement
004139  ** and/or current transaction is rolled back.
004140  */
004141  void sqlite3HaltConstraint(
004142    Parse *pParse,    /* Parsing context */
004143    int errCode,      /* extended error code */
004144    int onError,      /* Constraint type */
004145    char *p4,         /* Error message */
004146    i8 p4type,        /* P4_STATIC or P4_TRANSIENT */
004147    u8 p5Errmsg       /* P5_ErrMsg type */
004148  ){
004149    Vdbe *v = sqlite3GetVdbe(pParse);
004150    assert( (errCode&0xff)==SQLITE_CONSTRAINT );
004151    if( onError==OE_Abort ){
004152      sqlite3MayAbort(pParse);
004153    }
004154    sqlite3VdbeAddOp4(v, OP_Halt, errCode, onError, 0, p4, p4type);
004155    sqlite3VdbeChangeP5(v, p5Errmsg);
004156  }
004157  
004158  /*
004159  ** Code an OP_Halt due to UNIQUE or PRIMARY KEY constraint violation.
004160  */
004161  void sqlite3UniqueConstraint(
004162    Parse *pParse,    /* Parsing context */
004163    int onError,      /* Constraint type */
004164    Index *pIdx       /* The index that triggers the constraint */
004165  ){
004166    char *zErr;
004167    int j;
004168    StrAccum errMsg;
004169    Table *pTab = pIdx->pTable;
004170  
004171    sqlite3StrAccumInit(&errMsg, pParse->db, 0, 0, 200);
004172    if( pIdx->aColExpr ){
004173      sqlite3XPrintf(&errMsg, "index '%q'", pIdx->zName);
004174    }else{
004175      for(j=0; j<pIdx->nKeyCol; j++){
004176        char *zCol;
004177        assert( pIdx->aiColumn[j]>=0 );
004178        zCol = pTab->aCol[pIdx->aiColumn[j]].zName;
004179        if( j ) sqlite3StrAccumAppend(&errMsg, ", ", 2);
004180        sqlite3XPrintf(&errMsg, "%s.%s", pTab->zName, zCol);
004181      }
004182    }
004183    zErr = sqlite3StrAccumFinish(&errMsg);
004184    sqlite3HaltConstraint(pParse, 
004185      IsPrimaryKeyIndex(pIdx) ? SQLITE_CONSTRAINT_PRIMARYKEY 
004186                              : SQLITE_CONSTRAINT_UNIQUE,
004187      onError, zErr, P4_DYNAMIC, P5_ConstraintUnique);
004188  }
004189  
004190  
004191  /*
004192  ** Code an OP_Halt due to non-unique rowid.
004193  */
004194  void sqlite3RowidConstraint(
004195    Parse *pParse,    /* Parsing context */
004196    int onError,      /* Conflict resolution algorithm */
004197    Table *pTab       /* The table with the non-unique rowid */ 
004198  ){
004199    char *zMsg;
004200    int rc;
004201    if( pTab->iPKey>=0 ){
004202      zMsg = sqlite3MPrintf(pParse->db, "%s.%s", pTab->zName,
004203                            pTab->aCol[pTab->iPKey].zName);
004204      rc = SQLITE_CONSTRAINT_PRIMARYKEY;
004205    }else{
004206      zMsg = sqlite3MPrintf(pParse->db, "%s.rowid", pTab->zName);
004207      rc = SQLITE_CONSTRAINT_ROWID;
004208    }
004209    sqlite3HaltConstraint(pParse, rc, onError, zMsg, P4_DYNAMIC,
004210                          P5_ConstraintUnique);
004211  }
004212  
004213  /*
004214  ** Check to see if pIndex uses the collating sequence pColl.  Return
004215  ** true if it does and false if it does not.
004216  */
004217  #ifndef SQLITE_OMIT_REINDEX
004218  static int collationMatch(const char *zColl, Index *pIndex){
004219    int i;
004220    assert( zColl!=0 );
004221    for(i=0; i<pIndex->nColumn; i++){
004222      const char *z = pIndex->azColl[i];
004223      assert( z!=0 || pIndex->aiColumn[i]<0 );
004224      if( pIndex->aiColumn[i]>=0 && 0==sqlite3StrICmp(z, zColl) ){
004225        return 1;
004226      }
004227    }
004228    return 0;
004229  }
004230  #endif
004231  
004232  /*
004233  ** Recompute all indices of pTab that use the collating sequence pColl.
004234  ** If pColl==0 then recompute all indices of pTab.
004235  */
004236  #ifndef SQLITE_OMIT_REINDEX
004237  static void reindexTable(Parse *pParse, Table *pTab, char const *zColl){
004238    Index *pIndex;              /* An index associated with pTab */
004239  
004240    for(pIndex=pTab->pIndex; pIndex; pIndex=pIndex->pNext){
004241      if( zColl==0 || collationMatch(zColl, pIndex) ){
004242        int iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
004243        sqlite3BeginWriteOperation(pParse, 0, iDb);
004244        sqlite3RefillIndex(pParse, pIndex, -1);
004245      }
004246    }
004247  }
004248  #endif
004249  
004250  /*
004251  ** Recompute all indices of all tables in all databases where the
004252  ** indices use the collating sequence pColl.  If pColl==0 then recompute
004253  ** all indices everywhere.
004254  */
004255  #ifndef SQLITE_OMIT_REINDEX
004256  static void reindexDatabases(Parse *pParse, char const *zColl){
004257    Db *pDb;                    /* A single database */
004258    int iDb;                    /* The database index number */
004259    sqlite3 *db = pParse->db;   /* The database connection */
004260    HashElem *k;                /* For looping over tables in pDb */
004261    Table *pTab;                /* A table in the database */
004262  
004263    assert( sqlite3BtreeHoldsAllMutexes(db) );  /* Needed for schema access */
004264    for(iDb=0, pDb=db->aDb; iDb<db->nDb; iDb++, pDb++){
004265      assert( pDb!=0 );
004266      for(k=sqliteHashFirst(&pDb->pSchema->tblHash);  k; k=sqliteHashNext(k)){
004267        pTab = (Table*)sqliteHashData(k);
004268        reindexTable(pParse, pTab, zColl);
004269      }
004270    }
004271  }
004272  #endif
004273  
004274  /*
004275  ** Generate code for the REINDEX command.
004276  **
004277  **        REINDEX                            -- 1
004278  **        REINDEX  <collation>               -- 2
004279  **        REINDEX  ?<database>.?<tablename>  -- 3
004280  **        REINDEX  ?<database>.?<indexname>  -- 4
004281  **
004282  ** Form 1 causes all indices in all attached databases to be rebuilt.
004283  ** Form 2 rebuilds all indices in all databases that use the named
004284  ** collating function.  Forms 3 and 4 rebuild the named index or all
004285  ** indices associated with the named table.
004286  */
004287  #ifndef SQLITE_OMIT_REINDEX
004288  void sqlite3Reindex(Parse *pParse, Token *pName1, Token *pName2){
004289    CollSeq *pColl;             /* Collating sequence to be reindexed, or NULL */
004290    char *z;                    /* Name of a table or index */
004291    const char *zDb;            /* Name of the database */
004292    Table *pTab;                /* A table in the database */
004293    Index *pIndex;              /* An index associated with pTab */
004294    int iDb;                    /* The database index number */
004295    sqlite3 *db = pParse->db;   /* The database connection */
004296    Token *pObjName;            /* Name of the table or index to be reindexed */
004297  
004298    /* Read the database schema. If an error occurs, leave an error message
004299    ** and code in pParse and return NULL. */
004300    if( SQLITE_OK!=sqlite3ReadSchema(pParse) ){
004301      return;
004302    }
004303  
004304    if( pName1==0 ){
004305      reindexDatabases(pParse, 0);
004306      return;
004307    }else if( NEVER(pName2==0) || pName2->z==0 ){
004308      char *zColl;
004309      assert( pName1->z );
004310      zColl = sqlite3NameFromToken(pParse->db, pName1);
004311      if( !zColl ) return;
004312      pColl = sqlite3FindCollSeq(db, ENC(db), zColl, 0);
004313      if( pColl ){
004314        reindexDatabases(pParse, zColl);
004315        sqlite3DbFree(db, zColl);
004316        return;
004317      }
004318      sqlite3DbFree(db, zColl);
004319    }
004320    iDb = sqlite3TwoPartName(pParse, pName1, pName2, &pObjName);
004321    if( iDb<0 ) return;
004322    z = sqlite3NameFromToken(db, pObjName);
004323    if( z==0 ) return;
004324    zDb = db->aDb[iDb].zDbSName;
004325    pTab = sqlite3FindTable(db, z, zDb);
004326    if( pTab ){
004327      reindexTable(pParse, pTab, 0);
004328      sqlite3DbFree(db, z);
004329      return;
004330    }
004331    pIndex = sqlite3FindIndex(db, z, zDb);
004332    sqlite3DbFree(db, z);
004333    if( pIndex ){
004334      sqlite3BeginWriteOperation(pParse, 0, iDb);
004335      sqlite3RefillIndex(pParse, pIndex, -1);
004336      return;
004337    }
004338    sqlite3ErrorMsg(pParse, "unable to identify the object to be reindexed");
004339  }
004340  #endif
004341  
004342  /*
004343  ** Return a KeyInfo structure that is appropriate for the given Index.
004344  **
004345  ** The caller should invoke sqlite3KeyInfoUnref() on the returned object
004346  ** when it has finished using it.
004347  */
004348  KeyInfo *sqlite3KeyInfoOfIndex(Parse *pParse, Index *pIdx){
004349    int i;
004350    int nCol = pIdx->nColumn;
004351    int nKey = pIdx->nKeyCol;
004352    KeyInfo *pKey;
004353    if( pParse->nErr ) return 0;
004354    if( pIdx->uniqNotNull ){
004355      pKey = sqlite3KeyInfoAlloc(pParse->db, nKey, nCol-nKey);
004356    }else{
004357      pKey = sqlite3KeyInfoAlloc(pParse->db, nCol, 0);
004358    }
004359    if( pKey ){
004360      assert( sqlite3KeyInfoIsWriteable(pKey) );
004361      for(i=0; i<nCol; i++){
004362        const char *zColl = pIdx->azColl[i];
004363        pKey->aColl[i] = zColl==sqlite3StrBINARY ? 0 :
004364                          sqlite3LocateCollSeq(pParse, zColl);
004365        pKey->aSortOrder[i] = pIdx->aSortOrder[i];
004366      }
004367      if( pParse->nErr ){
004368        sqlite3KeyInfoUnref(pKey);
004369        pKey = 0;
004370      }
004371    }
004372    return pKey;
004373  }
004374  
004375  #ifndef SQLITE_OMIT_CTE
004376  /* 
004377  ** This routine is invoked once per CTE by the parser while parsing a 
004378  ** WITH clause. 
004379  */
004380  With *sqlite3WithAdd(
004381    Parse *pParse,          /* Parsing context */
004382    With *pWith,            /* Existing WITH clause, or NULL */
004383    Token *pName,           /* Name of the common-table */
004384    ExprList *pArglist,     /* Optional column name list for the table */
004385    Select *pQuery          /* Query used to initialize the table */
004386  ){
004387    sqlite3 *db = pParse->db;
004388    With *pNew;
004389    char *zName;
004390  
004391    /* Check that the CTE name is unique within this WITH clause. If
004392    ** not, store an error in the Parse structure. */
004393    zName = sqlite3NameFromToken(pParse->db, pName);
004394    if( zName && pWith ){
004395      int i;
004396      for(i=0; i<pWith->nCte; i++){
004397        if( sqlite3StrICmp(zName, pWith->a[i].zName)==0 ){
004398          sqlite3ErrorMsg(pParse, "duplicate WITH table name: %s", zName);
004399        }
004400      }
004401    }
004402  
004403    if( pWith ){
004404      int nByte = sizeof(*pWith) + (sizeof(pWith->a[1]) * pWith->nCte);
004405      pNew = sqlite3DbRealloc(db, pWith, nByte);
004406    }else{
004407      pNew = sqlite3DbMallocZero(db, sizeof(*pWith));
004408    }
004409    assert( (pNew!=0 && zName!=0) || db->mallocFailed );
004410  
004411    if( db->mallocFailed ){
004412      sqlite3ExprListDelete(db, pArglist);
004413      sqlite3SelectDelete(db, pQuery);
004414      sqlite3DbFree(db, zName);
004415      pNew = pWith;
004416    }else{
004417      pNew->a[pNew->nCte].pSelect = pQuery;
004418      pNew->a[pNew->nCte].pCols = pArglist;
004419      pNew->a[pNew->nCte].zName = zName;
004420      pNew->a[pNew->nCte].zCteErr = 0;
004421      pNew->nCte++;
004422    }
004423  
004424    return pNew;
004425  }
004426  
004427  /*
004428  ** Free the contents of the With object passed as the second argument.
004429  */
004430  void sqlite3WithDelete(sqlite3 *db, With *pWith){
004431    if( pWith ){
004432      int i;
004433      for(i=0; i<pWith->nCte; i++){
004434        struct Cte *pCte = &pWith->a[i];
004435        sqlite3ExprListDelete(db, pCte->pCols);
004436        sqlite3SelectDelete(db, pCte->pSelect);
004437        sqlite3DbFree(db, pCte->zName);
004438      }
004439      sqlite3DbFree(db, pWith);
004440    }
004441  }
004442  #endif /* !defined(SQLITE_OMIT_CTE) */