Exemple #1
0
static void sqliteOneHandler(Expr *pExpr, int lbl, int rev, Vdbe *v) {
  char *zExcep = sqliteStrNDup(pExpr->token.z, pExpr->token.n);

  assert( pExpr->op==TK_ID || pExpr->op==TK_STRING );
  sqliteDequote(zExcep);
  sqliteVdbeOp3(v, OP_ExcepWhen, rev, lbl, zExcep, P3_DYNAMIC);
}
Exemple #2
0
/*
** Add a new local variable to the block currently being constructed.
**
** The parser calls this routine once for each variable declaration
** in a DECLARE ... BEGIN statement.  sqliteStartBlock() gets called
** first to get things going.  Then this routine is called for each
** variable.
*/
void sqliteAddProcVar(Parse *pParse, Token *pName){
  Block *p;
  int i;
  char *z = 0;
  Variable *pVar;

  if( (p = pParse->pCurrentBlock)==0 ) return;
  sqliteSetNString(&z, pName->z, pName->n, 0);
  if( z==0 ) return;
  sqliteDequote(z);
  for(i=0; i<p->nVar; i++){
    if( strcmp(z, p->aVar[i].zName)==0 ){
      sqliteErrorMsg(pParse, "duplicate variable name: %s", z);
      sqliteFree(z);
      return;
    }
  }
  if( (p->nVar & 0x7)==0 ){
    Variable *aNew;
    aNew = sqliteRealloc( p->aVar, (p->nVar+8)*sizeof(p->aVar[0]));
    if( aNew==0 ) return;
    p->aVar = aNew;
  }
  pVar = &p->aVar[p->nVar];
  memset(pVar, 0, sizeof(p->aVar[0]));
  pVar->zName = z;
  pVar->mVar = pParse->nMem++;
  pVar->isParam = p->params;
  p->nVar++;
}
Exemple #3
0
/*
** Given the name of a variable, look up that name in the declarations of the
** current and enclosing blocks and make the pExpr expression node refer back
** to that variable's memory cell.  The following changes are made to pExpr:
**
**    pExpr->iColumn       Set to the number of the memory cell
**    pExpr->op            Set to TK_VAR.
**
** If the name cannot be resolved, leave an error message in pParse and return
** non-zero.  Return zero on success.
*/
int sqliteLookupVar(
  Parse *pParse,      /* The parsing context */
  Block *pBlock,	    /* The current block */
  Expr *pExpr         /* Make this EXPR node point to the selected variable */
){
  Block *b = pBlock;
  char *zVar;

  assert( pExpr->op==TK_ID || pExpr->op==TK_STRING );
  assert( pExpr->pLeft==0 && pExpr->pRight==0 );

  zVar = sqliteStrNDup(pExpr->token.z, pExpr->token.n);
  sqliteDequote(zVar);
  while( b ) {
	  int i;
	  for( i=0; i<b->nVar; i++ ) {
	    if( !strcmp(b->aVar[i].zName, zVar) ) {
          pExpr->iColumn  = b->aVar[i].mVar;
		  pExpr->op = TK_VAR;
		  if( b->aVar[i].notNull ){
		    pExpr->flags = EP_NotNull;
		  }
	      sqliteFree(zVar);
		  return 0;
	    }
	  }
    b = b->pParent;    
  }
  sqliteErrorMsg(pParse, "Variable %s not declared", zVar);
  sqliteFree(zVar);
  return 1;
}
Exemple #4
0
/*
** Add a new element to the end of an expression list.  If pList is
** initially NULL, then create a new expression list.
*/
ExprList *sqliteExprListAppend(ExprList *pList, Expr *pExpr, Token *pName){
  if( pList==0 ){
    pList = sqliteMalloc( sizeof(ExprList) );
    if( pList==0 ){
      /* sqliteExprDelete(pExpr); // Leak memory if malloc fails */
      return 0;
    }
    assert( pList->nAlloc==0 );
  }
  if( pList->nAlloc<=pList->nExpr ){
    pList->nAlloc = pList->nAlloc*2 + 4;
    pList->a = sqliteRealloc(pList->a, pList->nAlloc*sizeof(pList->a[0]));
    if( pList->a==0 ){
      /* sqliteExprDelete(pExpr); // Leak memory if malloc fails */
      pList->nExpr = pList->nAlloc = 0;
      return pList;
    }
  }
  assert( pList->a!=0 );
  if( pExpr || pName ){
    struct ExprList_item *pItem = &pList->a[pList->nExpr++];
    memset(pItem, 0, sizeof(*pItem));
    pItem->pExpr = pExpr;
    if( pName ){
      sqliteSetNString(&pItem->zName, pName->z, pName->n, 0);
      sqliteDequote(pItem->zName);
    }
  }
  return pList;
}
Exemple #5
0
void sqliteDropProc(Parse *pParse, Token *pName){
  Object *pObj;
  char *zName;
  Vdbe *v = sqliteGetVdbe(pParse);
  sqlite *db = pParse->db;

  zName = sqliteStrNDup(pName->z, pName->n);
  sqliteDequote(zName);
  pObj = sqliteHashFind(&(db->aDb[0].objectHash), zName, pName->n+1);
  if( !pParse->explain && !pObj ){
    sqliteErrorMsg(pParse, "no such object: %T", pName);
    goto dropobject_cleanup;
  }

  /* Generate code to destroy the database record of the trigger.
  */
  if( v ){
    int base;
    static VdbeOpList dropObject[] = {
      { OP_Rewind,     0, ADDR(9),  0},
      { OP_String,     0, 0,        0}, /* 1 */
      { OP_Column,     0, 1,        0},
      { OP_Ne,         0, ADDR(8),  0},
      { OP_String,     0, 0,        "procedure"},
      { OP_Column,     0, 0,        0},
      { OP_Ne,         0, ADDR(8),  0},
      { OP_Delete,     0, 0,        0},
      { OP_Next,       0, ADDR(1),  0}, /* 8 */
    };

    sqliteBeginWriteOperation(pParse, 0, 0);
    sqliteOpenMasterTable(v, 0);
    base = sqliteVdbeAddOpList(v,  ArraySize(dropObject), dropObject);
    sqliteVdbeChangeP3(v, base+1, zName, 0);
    if( pObj && pObj->iDb==0 ){
      sqliteChangeCookie(db, v);
    }
    sqliteVdbeAddOp(v, OP_Close, 0, 0);
    sqliteEndWriteOperation(pParse);
  }

  /*
   * If this is not an "explain", then delete the trigger structure.
   */
  if( !pParse->explain ){
    sqliteHashInsert(&(db->aDb[pObj->iDb].objectHash), zName, pName->n+1, 0);
    sqliteDeleteObject(pObj);
  }

dropobject_cleanup:
  sqliteFree(zName);
}
Exemple #6
0
/*
** If the P3 operand to the specified instruction appears
** to be a quoted string token, then this procedure removes 
** the quotes.
**
** The quoting operator can be either a grave ascent (ASCII 0x27)
** or a double quote character (ASCII 0x22).  Two quotes in a row
** resolve to be a single actual quote character within the string.
*/
void sqliteVdbeDequoteP3(Vdbe *p, int addr){
  Op *pOp;
  assert( p->magic==VDBE_MAGIC_INIT );
  if( p->aOp==0 ) return;
  if( addr<0 || addr>=p->nOp ){
    addr = p->nOp - 1;
    if( addr<0 ) return;
  }
  pOp = &p->aOp[addr];
  if( pOp->p3==0 || pOp->p3[0]==0 ) return;
  if( pOp->p3type==P3_POINTER ) return;
  if( pOp->p3type!=P3_DYNAMIC ){
    pOp->p3 = sqliteStrDup(pOp->p3);
    pOp->p3type = P3_DYNAMIC;
  }
  sqliteDequote(pOp->p3);
}
Exemple #7
0
static int sqliteCompileCall(
  Parse *pParse,
  Token *pName,
  ExprList *pEList
) {
  char *zName = 0;
  Vdbe *v = sqliteGetVdbe(pParse);
  Block *b = pParse->pCurrentBlock;
  Object * pObj = 0;
  sqlite *db = pParse->db;
  int i, nActual = 0;

  /* Check that the object exist & get its Object pointer*/
  zName = sqliteStrNDup(pName->z, pName->n);
  sqliteDequote(zName);
  pObj = sqliteHashFind(&(db->aDb[0].objectHash), zName,pName->n+1);
  if( !pObj ){
    sqliteErrorMsg(pParse, "object %T not found", pName);
    goto proc_cleanup;
  }
  if( pEList ) {
    nActual = pEList->nExpr;
  }
  if( pObj->nParam!=nActual ) {
  	sqliteErrorMsg(pParse, "bad parameter count for object %T", pName);
    goto proc_cleanup;
  }

  for(i=0; i<nActual; i++) {
	  Expr *pExpr = pEList->a[i].pExpr;
    if( sqliteExprProcResolve(pParse, b, pExpr) ){
      goto proc_cleanup;
    }
    if( sqliteExprCheck(pParse, pExpr, 0, 0) ){
      goto proc_cleanup;
    }
    sqliteExprCode(pParse, pExpr);
  }
  sqliteVdbeOp3(v, OP_Exec, nActual, 0, zName, P3_DYNAMIC);
  return 0;

proc_cleanup:
  sqliteFree(zName);
  return 1;
}
Exemple #8
0
void sqliteBeginProc(
  Parse *pParse,      /* The parse context of the statement */
  int what,           /* One of TK_PROCEDURE or TK_FUNCTION */
  Token *pName        /* The name of the object */
){
  Object *no;
  Block *pBlock = pParse->pCurrentBlock;
  char *zName = 0;        /* Name of the object */
  sqlite *db = pParse->db;

  /* Check that the object name does not already exist */
  zName = sqliteStrNDup(pName->z, pName->n);
  sqliteDequote(zName);
  if( !pParse->explain &&
	  sqliteHashFind(&(db->aDb[0].objectHash), zName,pName->n+1) ){
    sqliteErrorMsg(pParse, "object %T already exists", pName);
    goto object_cleanup;
  }
  /* Build the object */
  no = (Object*)sqliteMalloc(sizeof(Object));
  if( no==0 ) goto object_cleanup;
  no->name = zName;
  zName = 0;
  no->what = what;
  no->iDb = 0;
  no->nParam = pBlock->nVar;
  /* add param checks here */
  pBlock->pObj = no;
  pBlock->params = 0;
  assert( pParse->pNewTrigger==0 );
  pParse->pNewObject = no;
  return;

object_cleanup:
  sqliteFree(zName);
}
Exemple #9
0
/*
** This routine is called by the parser to process an ATTACH statement:
**
**     ATTACH DATABASE filename AS dbname
**
** The pFilename and pDbname arguments are the tokens that define the
** filename and dbname in the ATTACH statement.
*/
void sqliteAttach(Parse *pParse, Token *pFilename, Token *pDbname, Token *pKey){
  Db *aNew;
  int rc, i;
  char *zFile, *zName;
  sqlite *db;
  Vdbe *v;

  v = sqliteGetVdbe(pParse);
  sqliteVdbeAddOp(v, OP_Halt, 0, 0);
  if( pParse->explain ) return;
  db = pParse->db;
  if( db->file_format<4 ){
    sqliteErrorMsg(pParse, "cannot attach auxiliary databases to an "
       "older format master database", 0);
    pParse->rc = SQLITE_ERROR;
    return;
  }
  if( db->nDb>=MAX_ATTACHED+2 ){
    sqliteErrorMsg(pParse, "too many attached databases - max %d", 
       MAX_ATTACHED);
    pParse->rc = SQLITE_ERROR;
    return;
  }

  zFile = 0;
  sqliteSetNString(&zFile, pFilename->z, pFilename->n, 0);
  if( zFile==0 ) return;
  sqliteDequote(zFile);
#ifndef SQLITE_OMIT_AUTHORIZATION
  if( sqliteAuthCheck(pParse, SQLITE_ATTACH, zFile, 0, 0)!=SQLITE_OK ){
    sqliteFree(zFile);
    return;
  }
#endif /* SQLITE_OMIT_AUTHORIZATION */

  zName = 0;
  sqliteSetNString(&zName, pDbname->z, pDbname->n, 0);
  if( zName==0 ) return;
  sqliteDequote(zName);
  for(i=0; i<db->nDb; i++){
    if( db->aDb[i].zName && sqliteStrICmp(db->aDb[i].zName, zName)==0 ){
      sqliteErrorMsg(pParse, "database %z is already in use", zName);
      pParse->rc = SQLITE_ERROR;
      sqliteFree(zFile);
      return;
    }
  }

  if( db->aDb==db->aDbStatic ){
    aNew = sqliteMalloc( sizeof(db->aDb[0])*3 );
    if( aNew==0 ) return;
    memcpy(aNew, db->aDb, sizeof(db->aDb[0])*2);
  }else{
    aNew = sqliteRealloc(db->aDb, sizeof(db->aDb[0])*(db->nDb+1) );
    if( aNew==0 ) return;
  }
  db->aDb = aNew;
  aNew = &db->aDb[db->nDb++];
  memset(aNew, 0, sizeof(*aNew));
  sqliteHashInit(&aNew->tblHash, SQLITE_HASH_STRING, 0);
  sqliteHashInit(&aNew->idxHash, SQLITE_HASH_STRING, 0);
  sqliteHashInit(&aNew->trigHash, SQLITE_HASH_STRING, 0);
  sqliteHashInit(&aNew->aFKey, SQLITE_HASH_STRING, 1);
  aNew->zName = zName;
  rc = sqliteBtreeFactory(db, zFile, 0, MAX_PAGES, &aNew->pBt);
  if( rc ){
    sqliteErrorMsg(pParse, "unable to open database: %s", zFile);
  }
#if SQLITE_HAS_CODEC
  {
    extern int sqliteCodecAttach(sqlite*, int, void*, int);
    char *zKey = 0;
    int nKey;
    if( pKey && pKey->z && pKey->n ){
      sqliteSetNString(&zKey, pKey->z, pKey->n, 0);
      sqliteDequote(zKey);
      nKey = strlen(zKey);
    }else{
      zKey = 0;
      nKey = 0;
    }
    sqliteCodecAttach(db, db->nDb-1, zKey, nKey);
  }
#endif
  sqliteFree(zFile);
  db->flags &= ~SQLITE_Initialized;
  if( pParse->nErr ) return;
  if( rc==SQLITE_OK ){
    rc = sqliteInit(pParse->db, &pParse->zErrMsg);
  }
  if( rc ){
    int i = db->nDb - 1;
    assert( i>=2 );
    if( db->aDb[i].pBt ){
      sqliteBtreeClose(db->aDb[i].pBt);
      db->aDb[i].pBt = 0;
    }
    sqliteResetInternalSchema(db, 0);
    pParse->nErr++;
    pParse->rc = SQLITE_ERROR;
  }
}
Exemple #10
0
/*
** Process a pragma statement.  
**
** Pragmas are of this form:
**
**      PRAGMA id = value
**
** The identifier might also be a string.  The value is a string, and
** identifier, or a number.  If minusFlag is true, then the value is
** a number that was preceded by a minus sign.
*/
void sqlitePragma(Parse *pParse, Token *pLeft, Token *pRight, int minusFlag){
  char *zLeft = 0;
  char *zRight = 0;
  sqlite *db = pParse->db;
  Vdbe *v = sqliteGetVdbe(pParse);
  if( v==0 ) return;

  zLeft = sqliteStrNDup(pLeft->z, pLeft->n);
  sqliteDequote(zLeft);
  if( minusFlag ){
    zRight = 0;
    sqliteSetNString(&zRight, "-", 1, pRight->z, pRight->n, 0);
  }else{
    zRight = sqliteStrNDup(pRight->z, pRight->n);
    sqliteDequote(zRight);
  }
  if( sqliteAuthCheck(pParse, SQLITE_PRAGMA, zLeft, zRight, 0) ){
    sqliteFree(zLeft);
    sqliteFree(zRight);
    return;
  }
 
  /*
  **  PRAGMA default_cache_size
  **  PRAGMA default_cache_size=N
  **
  ** The first form reports the current persistent setting for the
  ** page cache size.  The value returned is the maximum number of
  ** pages in the page cache.  The second form sets both the current
  ** page cache size value and the persistent page cache size value
  ** stored in the database file.
  **
  ** The default cache size is stored in meta-value 2 of page 1 of the
  ** database file.  The cache size is actually the absolute value of
  ** this memory location.  The sign of meta-value 2 determines the
  ** synchronous setting.  A negative value means synchronous is off
  ** and a positive value means synchronous is on.
  */
  if( sqliteStrICmp(zLeft,"default_cache_size")==0 ){
    static VdbeOpList getCacheSize[] = {
      { OP_ReadCookie,  0, 2,        0},
      { OP_AbsValue,    0, 0,        0},
      { OP_Dup,         0, 0,        0},
      { OP_Integer,     0, 0,        0},
      { OP_Ne,          0, 6,        0},
      { OP_Integer,     0, 0,        0},  /* 5 */
      { OP_ColumnName,  0, 1,        "cache_size"},
      { OP_Callback,    1, 0,        0},
    };
    int addr;
    if( pRight->z==pLeft->z ){
      addr = sqliteVdbeAddOpList(v, ArraySize(getCacheSize), getCacheSize);
      sqliteVdbeChangeP1(v, addr+5, MAX_PAGES);
    }else{
      int size = atoi(zRight);
      if( size<0 ) size = -size;
      sqliteBeginWriteOperation(pParse, 0, 0);
      sqliteVdbeAddOp(v, OP_Integer, size, 0);
      sqliteVdbeAddOp(v, OP_ReadCookie, 0, 2);
      addr = sqliteVdbeAddOp(v, OP_Integer, 0, 0);
      sqliteVdbeAddOp(v, OP_Ge, 0, addr+3);
      sqliteVdbeAddOp(v, OP_Negative, 0, 0);
      sqliteVdbeAddOp(v, OP_SetCookie, 0, 2);
      sqliteEndWriteOperation(pParse);
      db->cache_size = db->cache_size<0 ? -size : size;
      sqliteBtreeSetCacheSize(db->aDb[0].pBt, db->cache_size);
    }
  }else

  /*
  **  PRAGMA cache_size
  **  PRAGMA cache_size=N
  **
  ** The first form reports the current local setting for the
  ** page cache size.  The local setting can be different from
  ** the persistent cache size value that is stored in the database
  ** file itself.  The value returned is the maximum number of
  ** pages in the page cache.  The second form sets the local
  ** page cache size value.  It does not change the persistent
  ** cache size stored on the disk so the cache size will revert
  ** to its default value when the database is closed and reopened.
  ** N should be a positive integer.
  */
  if( sqliteStrICmp(zLeft,"cache_size")==0 ){
    static VdbeOpList getCacheSize[] = {
      { OP_ColumnName,  0, 1,        "cache_size"},
      { OP_Callback,    1, 0,        0},
    };
    if( pRight->z==pLeft->z ){
      int size = db->cache_size;;
      if( size<0 ) size = -size;
      sqliteVdbeAddOp(v, OP_Integer, size, 0);
      sqliteVdbeAddOpList(v, ArraySize(getCacheSize), getCacheSize);
    }else{
      int size = atoi(zRight);
      if( size<0 ) size = -size;
      if( db->cache_size<0 ) size = -size;
      db->cache_size = size;
      sqliteBtreeSetCacheSize(db->aDb[0].pBt, db->cache_size);
    }
  }else

  /*
  **  PRAGMA default_synchronous
  **  PRAGMA default_synchronous=ON|OFF|NORMAL|FULL
  **
  ** The first form returns the persistent value of the "synchronous" setting
  ** that is stored in the database.  This is the synchronous setting that
  ** is used whenever the database is opened unless overridden by a separate
  ** "synchronous" pragma.  The second form changes the persistent and the
  ** local synchronous setting to the value given.
  **
  ** If synchronous is OFF, SQLite does not attempt any fsync() systems calls
  ** to make sure data is committed to disk.  Write operations are very fast,
  ** but a power failure can leave the database in an inconsistent state.
  ** If synchronous is ON or NORMAL, SQLite will do an fsync() system call to
  ** make sure data is being written to disk.  The risk of corruption due to
  ** a power loss in this mode is negligible but non-zero.  If synchronous
  ** is FULL, extra fsync()s occur to reduce the risk of corruption to near
  ** zero, but with a write performance penalty.  The default mode is NORMAL.
  */
  if( sqliteStrICmp(zLeft,"default_synchronous")==0 ){
    static VdbeOpList getSync[] = {
      { OP_ColumnName,  0, 1,        "synchronous"},
      { OP_ReadCookie,  0, 3,        0},
      { OP_Dup,         0, 0,        0},
      { OP_If,          0, 0,        0},  /* 3 */
      { OP_ReadCookie,  0, 2,        0},
      { OP_Integer,     0, 0,        0},
      { OP_Lt,          0, 5,        0},
      { OP_AddImm,      1, 0,        0},
      { OP_Callback,    1, 0,        0},
      { OP_Halt,        0, 0,        0},
      { OP_AddImm,     -1, 0,        0},  /* 10 */
      { OP_Callback,    1, 0,        0}
    };
    if( pRight->z==pLeft->z ){
      int addr = sqliteVdbeAddOpList(v, ArraySize(getSync), getSync);
      sqliteVdbeChangeP2(v, addr+3, addr+10);
    }else{
      int addr;
      int size = db->cache_size;
      if( size<0 ) size = -size;
      sqliteBeginWriteOperation(pParse, 0, 0);
      sqliteVdbeAddOp(v, OP_ReadCookie, 0, 2);
      sqliteVdbeAddOp(v, OP_Dup, 0, 0);
      addr = sqliteVdbeAddOp(v, OP_Integer, 0, 0);
      sqliteVdbeAddOp(v, OP_Ne, 0, addr+3);
      sqliteVdbeAddOp(v, OP_AddImm, MAX_PAGES, 0);
      sqliteVdbeAddOp(v, OP_AbsValue, 0, 0);
      db->safety_level = getSafetyLevel(zRight)+1;
      if( db->safety_level==1 ){
        sqliteVdbeAddOp(v, OP_Negative, 0, 0);
        size = -size;
      }
      sqliteVdbeAddOp(v, OP_SetCookie, 0, 2);
      sqliteVdbeAddOp(v, OP_Integer, db->safety_level, 0);
      sqliteVdbeAddOp(v, OP_SetCookie, 0, 3);
      sqliteEndWriteOperation(pParse);
      db->cache_size = size;
      sqliteBtreeSetCacheSize(db->aDb[0].pBt, db->cache_size);
      sqliteBtreeSetSafetyLevel(db->aDb[0].pBt, db->safety_level);
    }
  }else

  /*
  **   PRAGMA synchronous
  **   PRAGMA synchronous=OFF|ON|NORMAL|FULL
  **
  ** Return or set the local value of the synchronous flag.  Changing
  ** the local value does not make changes to the disk file and the
  ** default value will be restored the next time the database is
  ** opened.
  */
  if( sqliteStrICmp(zLeft,"synchronous")==0 ){
    static VdbeOpList getSync[] = {
      { OP_ColumnName,  0, 1,        "synchronous"},
      { OP_Callback,    1, 0,        0},
    };
    if( pRight->z==pLeft->z ){
      sqliteVdbeAddOp(v, OP_Integer, db->safety_level-1, 0);
      sqliteVdbeAddOpList(v, ArraySize(getSync), getSync);
    }else{
      int size = db->cache_size;
      if( size<0 ) size = -size;
      db->safety_level = getSafetyLevel(zRight)+1;
      if( db->safety_level==1 ) size = -size;
      db->cache_size = size;
      sqliteBtreeSetCacheSize(db->aDb[0].pBt, db->cache_size);
      sqliteBtreeSetSafetyLevel(db->aDb[0].pBt, db->safety_level);
    }
  }else

#ifndef NDEBUG
  if( sqliteStrICmp(zLeft, "trigger_overhead_test")==0 ){
    if( getBoolean(zRight) ){
      always_code_trigger_setup = 1;
    }else{
      always_code_trigger_setup = 0;
    }
  }else
#endif

  if( flagPragma(pParse, zLeft, zRight) ){
    /* The flagPragma() call also generates any necessary code */
  }else

  if( sqliteStrICmp(zLeft, "table_info")==0 ){
    Table *pTab;
    pTab = sqliteFindTable(db, zRight, 0);
    if( pTab ){
      static VdbeOpList tableInfoPreface[] = {
        { OP_ColumnName,  0, 0,       "cid"},
        { OP_ColumnName,  1, 0,       "name"},
        { OP_ColumnName,  2, 0,       "type"},
        { OP_ColumnName,  3, 0,       "notnull"},
        { OP_ColumnName,  4, 0,       "dflt_value"},
        { OP_ColumnName,  5, 1,       "pk"},
      };
      int i;
      sqliteVdbeAddOpList(v, ArraySize(tableInfoPreface), tableInfoPreface);
      sqliteViewGetColumnNames(pParse, pTab);
      for(i=0; i<pTab->nCol; i++){
        sqliteVdbeAddOp(v, OP_Integer, i, 0);
        sqliteVdbeOp3(v, OP_String, 0, 0, pTab->aCol[i].zName, 0);
        sqliteVdbeOp3(v, OP_String, 0, 0,
           pTab->aCol[i].zType ? pTab->aCol[i].zType : "numeric", 0);
        sqliteVdbeAddOp(v, OP_Integer, pTab->aCol[i].notNull, 0);
        sqliteVdbeOp3(v, OP_String, 0, 0,
           pTab->aCol[i].zDflt, P3_STATIC);
        sqliteVdbeAddOp(v, OP_Integer, pTab->aCol[i].isPrimKey, 0);
        sqliteVdbeAddOp(v, OP_Callback, 6, 0);
      }
    }
  }else

  if( sqliteStrICmp(zLeft, "index_info")==0 ){
    Index *pIdx;
    Table *pTab;
    pIdx = sqliteFindIndex(db, zRight, 0);
    if( pIdx ){
      static VdbeOpList tableInfoPreface[] = {
        { OP_ColumnName,  0, 0,       "seqno"},
        { OP_ColumnName,  1, 0,       "cid"},
        { OP_ColumnName,  2, 1,       "name"},
      };
      int i;
      pTab = pIdx->pTable;
      sqliteVdbeAddOpList(v, ArraySize(tableInfoPreface), tableInfoPreface);
      for(i=0; i<pIdx->nColumn; i++){
        int cnum = pIdx->aiColumn[i];
        sqliteVdbeAddOp(v, OP_Integer, i, 0);
        sqliteVdbeAddOp(v, OP_Integer, cnum, 0);
        assert( pTab->nCol>cnum );
        sqliteVdbeOp3(v, OP_String, 0, 0, pTab->aCol[cnum].zName, 0);
        sqliteVdbeAddOp(v, OP_Callback, 3, 0);
      }
    }
  }else

  if( sqliteStrICmp(zLeft, "index_list")==0 ){
    Index *pIdx;
    Table *pTab;
    pTab = sqliteFindTable(db, zRight, 0);
    if( pTab ){
      v = sqliteGetVdbe(pParse);
      pIdx = pTab->pIndex;
    }
    if( pTab && pIdx ){
      int i = 0; 
      static VdbeOpList indexListPreface[] = {
        { OP_ColumnName,  0, 0,       "seq"},
        { OP_ColumnName,  1, 0,       "name"},
        { OP_ColumnName,  2, 1,       "unique"},
      };

      sqliteVdbeAddOpList(v, ArraySize(indexListPreface), indexListPreface);
      while(pIdx){
        sqliteVdbeAddOp(v, OP_Integer, i, 0);
        sqliteVdbeOp3(v, OP_String, 0, 0, pIdx->zName, 0);
        sqliteVdbeAddOp(v, OP_Integer, pIdx->onError!=OE_None, 0);
        sqliteVdbeAddOp(v, OP_Callback, 3, 0);
        ++i;
        pIdx = pIdx->pNext;
      }
    }
  }else

  if( sqliteStrICmp(zLeft, "foreign_key_list")==0 ){
    FKey *pFK;
    Table *pTab;
    pTab = sqliteFindTable(db, zRight, 0);
    if( pTab ){
      v = sqliteGetVdbe(pParse);
      pFK = pTab->pFKey;
    }
    if( pTab && pFK ){
      int i = 0; 
      static VdbeOpList indexListPreface[] = {
        { OP_ColumnName,  0, 0,       "id"},
        { OP_ColumnName,  1, 0,       "seq"},
        { OP_ColumnName,  2, 0,       "table"},
        { OP_ColumnName,  3, 0,       "from"},
        { OP_ColumnName,  4, 1,       "to"},
      };

      sqliteVdbeAddOpList(v, ArraySize(indexListPreface), indexListPreface);
      while(pFK){
        int j;
        for(j=0; j<pFK->nCol; j++){
          sqliteVdbeAddOp(v, OP_Integer, i, 0);
          sqliteVdbeAddOp(v, OP_Integer, j, 0);
          sqliteVdbeOp3(v, OP_String, 0, 0, pFK->zTo, 0);
          sqliteVdbeOp3(v, OP_String, 0, 0,
                           pTab->aCol[pFK->aCol[j].iFrom].zName, 0);
          sqliteVdbeOp3(v, OP_String, 0, 0, pFK->aCol[j].zCol, 0);
          sqliteVdbeAddOp(v, OP_Callback, 5, 0);
        }
        ++i;
        pFK = pFK->pNextFrom;
      }
    }
  }else

  if( sqliteStrICmp(zLeft, "database_list")==0 ){
    int i;
    static VdbeOpList indexListPreface[] = {
      { OP_ColumnName,  0, 0,       "seq"},
      { OP_ColumnName,  1, 0,       "name"},
      { OP_ColumnName,  2, 1,       "file"},
    };

    sqliteVdbeAddOpList(v, ArraySize(indexListPreface), indexListPreface);
    for(i=0; i<db->nDb; i++){
      if( db->aDb[i].pBt==0 ) continue;
      assert( db->aDb[i].zName!=0 );
      sqliteVdbeAddOp(v, OP_Integer, i, 0);
      sqliteVdbeOp3(v, OP_String, 0, 0, db->aDb[i].zName, 0);
      sqliteVdbeOp3(v, OP_String, 0, 0,
           sqliteBtreeGetFilename(db->aDb[i].pBt), 0);
      sqliteVdbeAddOp(v, OP_Callback, 3, 0);
    }
  }else


  /*
  **   PRAGMA temp_store
  **   PRAGMA temp_store = "default"|"memory"|"file"
  **
  ** Return or set the local value of the temp_store flag.  Changing
  ** the local value does not make changes to the disk file and the default
  ** value will be restored the next time the database is opened.
  **
  ** Note that it is possible for the library compile-time options to
  ** override this setting
  */
  if( sqliteStrICmp(zLeft, "temp_store")==0 ){
    static VdbeOpList getTmpDbLoc[] = {
      { OP_ColumnName,  0, 1,        "temp_store"},
      { OP_Callback,    1, 0,        0},
    };
    if( pRight->z==pLeft->z ){
      sqliteVdbeAddOp(v, OP_Integer, db->temp_store, 0);
      sqliteVdbeAddOpList(v, ArraySize(getTmpDbLoc), getTmpDbLoc);
    }else{
      changeTempStorage(pParse, zRight);
    }
  }else

  /*
  **   PRAGMA default_temp_store
  **   PRAGMA default_temp_store = "default"|"memory"|"file"
  **
  ** Return or set the value of the persistent temp_store flag.  Any
  ** change does not take effect until the next time the database is
  ** opened.
  **
  ** Note that it is possible for the library compile-time options to
  ** override this setting
  */
  if( sqliteStrICmp(zLeft, "default_temp_store")==0 ){
    static VdbeOpList getTmpDbLoc[] = {
      { OP_ColumnName,  0, 1,        "temp_store"},
      { OP_ReadCookie,  0, 5,        0},
      { OP_Callback,    1, 0,        0}};
    if( pRight->z==pLeft->z ){
      sqliteVdbeAddOpList(v, ArraySize(getTmpDbLoc), getTmpDbLoc);
    }else{
      sqliteBeginWriteOperation(pParse, 0, 0);
      sqliteVdbeAddOp(v, OP_Integer, getTempStore(zRight), 0);
      sqliteVdbeAddOp(v, OP_SetCookie, 0, 5);
      sqliteEndWriteOperation(pParse);
    }
  }else

#ifndef NDEBUG
  if( sqliteStrICmp(zLeft, "parser_trace")==0 ){
    extern void sqliteParserTrace(FILE*, char *);
    if( getBoolean(zRight) ){
      sqliteParserTrace(stdout, "parser: ");
    }else{
      sqliteParserTrace(0, 0);
    }
  }else
#endif

  if( sqliteStrICmp(zLeft, "integrity_check")==0 ){
    int i, j, addr;

    /* Code that initializes the integrity check program.  Set the
    ** error count 0
    */
    static VdbeOpList initCode[] = {
      { OP_Integer,     0, 0,        0},
      { OP_MemStore,    0, 1,        0},
      { OP_ColumnName,  0, 1,        "integrity_check"},
    };

    /* Code to do an BTree integrity check on a single database file.
    */
    static VdbeOpList checkDb[] = {
      { OP_SetInsert,   0, 0,        "2"},
      { OP_Integer,     0, 0,        0},    /* 1 */
      { OP_OpenRead,    0, 2,        0},
      { OP_Rewind,      0, 7,        0},    /* 3 */
      { OP_Column,      0, 3,        0},    /* 4 */
      { OP_SetInsert,   0, 0,        0},
      { OP_Next,        0, 4,        0},    /* 6 */
      { OP_IntegrityCk, 0, 0,        0},    /* 7 */
      { OP_Dup,         0, 1,        0},
      { OP_String,      0, 0,        "ok"},
      { OP_StrEq,       0, 12,       0},    /* 10 */
      { OP_MemIncr,     0, 0,        0},
      { OP_String,      0, 0,        "*** in database "},
      { OP_String,      0, 0,        0},    /* 13 */
      { OP_String,      0, 0,        " ***\n"},
      { OP_Pull,        3, 0,        0},
      { OP_Concat,      4, 1,        0},
      { OP_Callback,    1, 0,        0},
    };

    /* Code that appears at the end of the integrity check.  If no error
    ** messages have been generated, output OK.  Otherwise output the
    ** error message
    */
    static VdbeOpList endCode[] = {
      { OP_MemLoad,     0, 0,        0},
      { OP_Integer,     0, 0,        0},
      { OP_Ne,          0, 0,        0},    /* 2 */
      { OP_String,      0, 0,        "ok"},
      { OP_Callback,    1, 0,        0},
    };

    /* Initialize the VDBE program */
    sqliteVdbeAddOpList(v, ArraySize(initCode), initCode);

    /* Do an integrity check on each database file */
    for(i=0; i<db->nDb; i++){
      HashElem *x;

      /* Do an integrity check of the B-Tree
      */
      addr = sqliteVdbeAddOpList(v, ArraySize(checkDb), checkDb);
      sqliteVdbeChangeP1(v, addr+1, i);
      sqliteVdbeChangeP2(v, addr+3, addr+7);
      sqliteVdbeChangeP2(v, addr+6, addr+4);
      sqliteVdbeChangeP2(v, addr+7, i);
      sqliteVdbeChangeP2(v, addr+10, addr+ArraySize(checkDb));
      sqliteVdbeChangeP3(v, addr+13, db->aDb[i].zName, P3_STATIC);

      /* Make sure all the indices are constructed correctly.
      */
      sqliteCodeVerifySchema(pParse, i);
      for(x=sqliteHashFirst(&db->aDb[i].tblHash); x; x=sqliteHashNext(x)){
        Table *pTab = sqliteHashData(x);
        Index *pIdx;
        int loopTop;

        if( pTab->pIndex==0 ) continue;
        sqliteVdbeAddOp(v, OP_Integer, i, 0);
        sqliteVdbeOp3(v, OP_OpenRead, 1, pTab->tnum, pTab->zName, 0);
        for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){
          if( pIdx->tnum==0 ) continue;
          sqliteVdbeAddOp(v, OP_Integer, pIdx->iDb, 0);
          sqliteVdbeOp3(v, OP_OpenRead, j+2, pIdx->tnum, pIdx->zName, 0);
        }
        sqliteVdbeAddOp(v, OP_Integer, 0, 0);
        sqliteVdbeAddOp(v, OP_MemStore, 1, 1);
        loopTop = sqliteVdbeAddOp(v, OP_Rewind, 1, 0);
        sqliteVdbeAddOp(v, OP_MemIncr, 1, 0);
        for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){
          int k, jmp2;
          static VdbeOpList idxErr[] = {
            { OP_MemIncr,     0,  0,  0},
            { OP_String,      0,  0,  "rowid "},
            { OP_Recno,       1,  0,  0},
            { OP_String,      0,  0,  " missing from index "},
            { OP_String,      0,  0,  0},    /* 4 */
            { OP_Concat,      4,  0,  0},
            { OP_Callback,    1,  0,  0},
          };
          sqliteVdbeAddOp(v, OP_Recno, 1, 0);
          for(k=0; k<pIdx->nColumn; k++){
            int idx = pIdx->aiColumn[k];
            if( idx==pTab->iPKey ){
              sqliteVdbeAddOp(v, OP_Recno, 1, 0);
            }else{
              sqliteVdbeAddOp(v, OP_Column, 1, idx);
            }
          }
          sqliteVdbeAddOp(v, OP_MakeIdxKey, pIdx->nColumn, 0);
          if( db->file_format>=4 ) sqliteAddIdxKeyType(v, pIdx);
          jmp2 = sqliteVdbeAddOp(v, OP_Found, j+2, 0);
          addr = sqliteVdbeAddOpList(v, ArraySize(idxErr), idxErr);
          sqliteVdbeChangeP3(v, addr+4, pIdx->zName, P3_STATIC);
          sqliteVdbeChangeP2(v, jmp2, sqliteVdbeCurrentAddr(v));
        }
        sqliteVdbeAddOp(v, OP_Next, 1, loopTop+1);
        sqliteVdbeChangeP2(v, loopTop, sqliteVdbeCurrentAddr(v));
        for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){
          static VdbeOpList cntIdx[] = {
             { OP_Integer,      0,  0,  0},
             { OP_MemStore,     2,  1,  0},
             { OP_Rewind,       0,  0,  0},  /* 2 */
             { OP_MemIncr,      2,  0,  0},
             { OP_Next,         0,  0,  0},  /* 4 */
             { OP_MemLoad,      1,  0,  0},
             { OP_MemLoad,      2,  0,  0},
             { OP_Eq,           0,  0,  0},  /* 7 */
             { OP_MemIncr,      0,  0,  0},
             { OP_String,       0,  0,  "wrong # of entries in index "},
             { OP_String,       0,  0,  0},  /* 10 */
             { OP_Concat,       2,  0,  0},
             { OP_Callback,     1,  0,  0},
          };
          if( pIdx->tnum==0 ) continue;
          addr = sqliteVdbeAddOpList(v, ArraySize(cntIdx), cntIdx);
          sqliteVdbeChangeP1(v, addr+2, j+2);
          sqliteVdbeChangeP2(v, addr+2, addr+5);
          sqliteVdbeChangeP1(v, addr+4, j+2);
          sqliteVdbeChangeP2(v, addr+4, addr+3);
          sqliteVdbeChangeP2(v, addr+7, addr+ArraySize(cntIdx));
          sqliteVdbeChangeP3(v, addr+10, pIdx->zName, P3_STATIC);
        }
      } 
    }
    addr = sqliteVdbeAddOpList(v, ArraySize(endCode), endCode);
    sqliteVdbeChangeP2(v, addr+2, addr+ArraySize(endCode));
  }else

  {}
  sqliteFree(zLeft);
  sqliteFree(zRight);
}
Exemple #11
0
/*
** This is called by the parser when it sees a CREATE TRIGGER statement
** up to the point of the BEGIN before the trigger actions.  A Trigger
** structure is generated based on the information available and stored
** in pParse->pNewTrigger.  After the trigger actions have been parsed, the
** sqliteFinishTrigger() function is called to complete the trigger
** construction process.
*/
void sqliteBeginTrigger(
  Parse *pParse,      /* The parse context of the CREATE TRIGGER statement */
  Token *pName,       /* The name of the trigger */
  int tr_tm,          /* One of TK_BEFORE, TK_AFTER, TK_INSTEAD */
  int op,             /* One of TK_INSERT, TK_UPDATE, TK_DELETE */
  IdList *pColumns,   /* column list if this is an UPDATE OF trigger */
  SrcList *pTableName,/* The name of the table/view the trigger applies to */
  int foreach,        /* One of TK_ROW or TK_STATEMENT */
  Expr *pWhen,        /* WHEN clause */
  int isTemp          /* True if the TEMPORARY keyword is present */
){
  Trigger *nt;
  Table   *tab;
  char *zName = 0;        /* Name of the trigger */
  sqlite *db = pParse->db;
  int iDb;                /* When database to store the trigger in */
  DbFixer sFix;

  /* Check that: 
  ** 1. the trigger name does not already exist.
  ** 2. the table (or view) does exist in the same database as the trigger.
  ** 3. that we are not trying to create a trigger on the sqlite_master table
  ** 4. That we are not trying to create an INSTEAD OF trigger on a table.
  ** 5. That we are not trying to create a BEFORE or AFTER trigger on a view.
  */
  if( sqlite_malloc_failed ) goto trigger_cleanup;
  assert( pTableName->nSrc==1 );
  if( db->init.busy
   && sqliteFixInit(&sFix, pParse, db->init.iDb, "trigger", pName)
   && sqliteFixSrcList(&sFix, pTableName)
  ){
    goto trigger_cleanup;
  }
  tab = sqliteSrcListLookup(pParse, pTableName);
  if( !tab ){
    goto trigger_cleanup;
  }
  iDb = isTemp ? 1 : tab->iDb;
  if( iDb>=2 && !db->init.busy ){
    sqliteErrorMsg(pParse, "triggers may not be added to auxiliary "
       "database %s", db->aDb[tab->iDb].zName);
    goto trigger_cleanup;
  }

  zName = sqliteStrNDup(pName->z, pName->n);
  sqliteDequote(zName);
  if( sqliteHashFind(&(db->aDb[iDb].trigHash), zName,pName->n+1) ){
    sqliteErrorMsg(pParse, "trigger %T already exists", pName);
    goto trigger_cleanup;
  }
  if( sqliteStrNICmp(tab->zName, "sqlite_", 7)==0 ){
    sqliteErrorMsg(pParse, "cannot create trigger on system table");
    pParse->nErr++;
    goto trigger_cleanup;
  }
  if( tab->pSelect && tr_tm != TK_INSTEAD ){
    sqliteErrorMsg(pParse, "cannot create %s trigger on view: %S", 
        (tr_tm == TK_BEFORE)?"BEFORE":"AFTER", pTableName, 0);
    goto trigger_cleanup;
  }
  if( !tab->pSelect && tr_tm == TK_INSTEAD ){
    sqliteErrorMsg(pParse, "cannot create INSTEAD OF"
        " trigger on table: %S", pTableName, 0);
    goto trigger_cleanup;
  }
#ifndef SQLITE_OMIT_AUTHORIZATION
  {
    int code = SQLITE_CREATE_TRIGGER;
    const char *zDb = db->aDb[tab->iDb].zName;
    const char *zDbTrig = isTemp ? db->aDb[1].zName : zDb;
    if( tab->iDb==1 || isTemp ) code = SQLITE_CREATE_TEMP_TRIGGER;
    if( sqliteAuthCheck(pParse, code, zName, tab->zName, zDbTrig) ){
      goto trigger_cleanup;
    }
    if( sqliteAuthCheck(pParse, SQLITE_INSERT, SCHEMA_TABLE(tab->iDb), 0, zDb)){
      goto trigger_cleanup;
    }
  }
#endif

  /* INSTEAD OF triggers can only appear on views and BEGIN triggers
  ** cannot appear on views.  So we might as well translate every
  ** INSTEAD OF trigger into a BEFORE trigger.  It simplifies code
  ** elsewhere.
  */
  if (tr_tm == TK_INSTEAD){
    tr_tm = TK_BEFORE;
  }

  /* Build the Trigger object */
  nt = (Trigger*)sqliteMalloc(sizeof(Trigger));
  if( nt==0 ) goto trigger_cleanup;
  nt->name = zName;
  zName = 0;
  nt->table = sqliteStrDup(pTableName->a[0].zName);
  if( sqlite_malloc_failed ) goto trigger_cleanup;
  nt->iDb = iDb;
  nt->iTabDb = tab->iDb;
  nt->op = op;
  nt->tr_tm = tr_tm;
  nt->pWhen = sqliteExprDup(pWhen);
  nt->pColumns = sqliteIdListDup(pColumns);
  nt->foreach = foreach;
  sqliteTokenCopy(&nt->nameToken,pName);
  assert( pParse->pNewTrigger==0 );
  pParse->pNewTrigger = nt;

trigger_cleanup:
  sqliteFree(zName);
  sqliteSrcListDelete(pTableName);
  sqliteIdListDelete(pColumns);
  sqliteExprDelete(pWhen);
}
Exemple #12
0
/*
** The COPY command is for compatibility with PostgreSQL and specificially
** for the ability to read the output of pg_dump.  The format is as
** follows:
**
**    COPY table FROM file [USING DELIMITERS string]
**
** "table" is an existing table name.  We will read lines of code from
** file to fill this table with data.  File might be "stdin".  The optional
** delimiter string identifies the field separators.  The default is a tab.
*/
void sqliteCopy(
  Parse *pParse,       /* The parser context */
  SrcList *pTableName, /* The name of the table into which we will insert */
  Token *pFilename,    /* The file from which to obtain information */
  Token *pDelimiter,   /* Use this as the field delimiter */
  int onError          /* What to do if a constraint fails */
){
  Table *pTab;
  int i;
  Vdbe *v;
  int addr, end;
  char *zFile = 0;
  const char *zDb;
  sqlite *db = pParse->db;


  if( sqlite_malloc_failed  ) goto copy_cleanup;
  assert( pTableName->nSrc==1 );
  pTab = sqliteSrcListLookup(pParse, pTableName);
  if( pTab==0 || sqliteIsReadOnly(pParse, pTab, 0) ) goto copy_cleanup;
  zFile = sqliteStrNDup(pFilename->z, pFilename->n);
  sqliteDequote(zFile);
  assert( pTab->iDb<db->nDb );
  zDb = db->aDb[pTab->iDb].zName;
  if( sqliteAuthCheck(pParse, SQLITE_INSERT, pTab->zName, 0, zDb)
      || sqliteAuthCheck(pParse, SQLITE_COPY, pTab->zName, zFile, zDb) ){
    goto copy_cleanup;
  }
  v = sqliteGetVdbe(pParse);
  if( v ){
    sqliteBeginWriteOperation(pParse, 1, pTab->iDb);
    addr = sqliteVdbeOp3(v, OP_FileOpen, 0, 0, pFilename->z, pFilename->n);
    sqliteVdbeDequoteP3(v, addr);
    sqliteOpenTableAndIndices(pParse, pTab, 0);
    if( db->flags & SQLITE_CountRows ){
      sqliteVdbeAddOp(v, OP_Integer, 0, 0);  /* Initialize the row count */
    }
    end = sqliteVdbeMakeLabel(v);
    addr = sqliteVdbeAddOp(v, OP_FileRead, pTab->nCol, end);
    if( pDelimiter ){
      sqliteVdbeChangeP3(v, addr, pDelimiter->z, pDelimiter->n);
      sqliteVdbeDequoteP3(v, addr);
    }else{
      sqliteVdbeChangeP3(v, addr, "\t", 1);
    }
    if( pTab->iPKey>=0 ){
      sqliteVdbeAddOp(v, OP_FileColumn, pTab->iPKey, 0);
      sqliteVdbeAddOp(v, OP_MustBeInt, 0, 0);
    }else{
      sqliteVdbeAddOp(v, OP_NewRecno, 0, 0);
    }
    for(i=0; i<pTab->nCol; i++){
      if( i==pTab->iPKey ){
        /* The integer primary key column is filled with NULL since its
        ** value is always pulled from the record number */
        sqliteVdbeAddOp(v, OP_String, 0, 0);
      }else{
        sqliteVdbeAddOp(v, OP_FileColumn, i, 0);
      }
    }
    sqliteGenerateConstraintChecks(pParse, pTab, 0, 0, pTab->iPKey>=0, 
                                   0, onError, addr);
    sqliteCompleteInsertion(pParse, pTab, 0, 0, 0, 0, -1);
    if( (db->flags & SQLITE_CountRows)!=0 ){
      sqliteVdbeAddOp(v, OP_AddImm, 1, 0);  /* Increment row count */
    }
    sqliteVdbeAddOp(v, OP_Goto, 0, addr);
    sqliteVdbeResolveLabel(v, end);
    sqliteVdbeAddOp(v, OP_Noop, 0, 0);
    sqliteEndWriteOperation(pParse);
    if( db->flags & SQLITE_CountRows ){
      sqliteVdbeAddOp(v, OP_ColumnName, 0, 1);
      sqliteVdbeChangeP3(v, -1, "rows inserted", P3_STATIC);
      sqliteVdbeAddOp(v, OP_Callback, 1, 0);
    }
  }
  
copy_cleanup:
  sqliteSrcListDelete(pTableName);
  sqliteFree(zFile);
  return;
}
Exemple #13
0
/*
** Given the name of a column of the form X.Y.Z or Y.Z or just Z, look up
** that name in the set of source tables in pSrcList and make the pExpr 
** expression node refer back to that source column.  The following changes
** are made to pExpr:
**
**    pExpr->iDb           Set the index in db->aDb[] of the database holding
**                         the table.
**    pExpr->iTable        Set to the cursor number for the table obtained
**                         from pSrcList.
**    pExpr->iColumn       Set to the column number within the table.
**    pExpr->dataType      Set to the appropriate data type for the column.
**    pExpr->op            Set to TK_COLUMN.
**    pExpr->pLeft         Any expression this points to is deleted
**    pExpr->pRight        Any expression this points to is deleted.
**
** The pDbToken is the name of the database (the "X").  This value may be
** NULL meaning that name is of the form Y.Z or Z.  Any available database
** can be used.  The pTableToken is the name of the table (the "Y").  This
** value can be NULL if pDbToken is also NULL.  If pTableToken is NULL it
** means that the form of the name is Z and that columns from any table
** can be used.
**
** If the name cannot be resolved unambiguously, leave an error message
** in pParse and return non-zero.  Return zero on success.
*/
static int lookupName(
  Parse *pParse,      /* The parsing context */
  Token *pDbToken,     /* Name of the database containing table, or NULL */
  Token *pTableToken,  /* Name of table containing column, or NULL */
  Token *pColumnToken, /* Name of the column. */
  SrcList *pSrcList,   /* List of tables used to resolve column names */
  ExprList *pEList,    /* List of expressions used to resolve "AS" */
  Expr *pExpr          /* Make this EXPR node point to the selected column */
){
  char *zDb = 0;       /* Name of the database.  The "X" in X.Y.Z */
  char *zTab = 0;      /* Name of the table.  The "Y" in X.Y.Z or Y.Z */
  char *zCol = 0;      /* Name of the column.  The "Z" */
  int i, j;            /* Loop counters */
  int cnt = 0;         /* Number of matching column names */
  int cntTab = 0;      /* Number of matching table names */
  sqlite *db = pParse->db;  /* The database */

  assert( pColumnToken && pColumnToken->z ); /* The Z in X.Y.Z cannot be NULL */
  if( pDbToken && pDbToken->z ){
    zDb = sqliteStrNDup(pDbToken->z, pDbToken->n);
    sqliteDequote(zDb);
  }else{
    zDb = 0;
  }
  if( pTableToken && pTableToken->z ){
    zTab = sqliteStrNDup(pTableToken->z, pTableToken->n);
    sqliteDequote(zTab);
  }else{
    assert( zDb==0 );
    zTab = 0;
  }
  zCol = sqliteStrNDup(pColumnToken->z, pColumnToken->n);
  sqliteDequote(zCol);
  if( sqlite_malloc_failed ){
    return 1;  /* Leak memory (zDb and zTab) if malloc fails */
  }
  assert( zTab==0 || pEList==0 );

  pExpr->iTable = -1;
  for(i=0; i<pSrcList->nSrc; i++){
    struct SrcList_item *pItem = &pSrcList->a[i];
    Table *pTab = pItem->pTab;
    Column *pCol;

    if( pTab==0 ) continue;
    assert( pTab->nCol>0 );
    if( zTab ){
      if( pItem->zAlias ){
        char *zTabName = pItem->zAlias;
        if( sqliteStrICmp(zTabName, zTab)!=0 ) continue;
      }else{
        char *zTabName = pTab->zName;
        if( zTabName==0 || sqliteStrICmp(zTabName, zTab)!=0 ) continue;
        if( zDb!=0 && sqliteStrICmp(db->aDb[pTab->iDb].zName, zDb)!=0 ){
          continue;
        }
      }
    }
    if( 0==(cntTab++) ){
      pExpr->iTable = pItem->iCursor;
      pExpr->iDb = pTab->iDb;
    }
    for(j=0, pCol=pTab->aCol; j<pTab->nCol; j++, pCol++){
      if( sqliteStrICmp(pCol->zName, zCol)==0 ){
        cnt++;
        pExpr->iTable = pItem->iCursor;
        pExpr->iDb = pTab->iDb;
        /* Substitute the rowid (column -1) for the INTEGER PRIMARY KEY */
        pExpr->iColumn = j==pTab->iPKey ? -1 : j;
        pExpr->dataType = pCol->sortOrder & SQLITE_SO_TYPEMASK;
        break;
      }
    }
  }

  /* If we have not already resolved the name, then maybe 
  ** it is a new.* or old.* trigger argument reference
  */
  if( zDb==0 && zTab!=0 && cnt==0 && pParse->trigStack!=0 ){
    TriggerStack *pTriggerStack = pParse->trigStack;
    Table *pTab = 0;
    if( pTriggerStack->newIdx != -1 && sqliteStrICmp("new", zTab) == 0 ){
      pExpr->iTable = pTriggerStack->newIdx;
      assert( pTriggerStack->pTab );
      pTab = pTriggerStack->pTab;
    }else if( pTriggerStack->oldIdx != -1 && sqliteStrICmp("old", zTab) == 0 ){
      pExpr->iTable = pTriggerStack->oldIdx;
      assert( pTriggerStack->pTab );
      pTab = pTriggerStack->pTab;
    }

    if( pTab ){ 
      int j;
      Column *pCol = pTab->aCol;
      
      pExpr->iDb = pTab->iDb;
      cntTab++;
      for(j=0; j < pTab->nCol; j++, pCol++) {
        if( sqliteStrICmp(pCol->zName, zCol)==0 ){
          cnt++;
          pExpr->iColumn = j==pTab->iPKey ? -1 : j;
          pExpr->dataType = pCol->sortOrder & SQLITE_SO_TYPEMASK;
          break;
        }
      }
    }
  }

  /*
  ** Perhaps the name is a reference to the ROWID
  */
  if( cnt==0 && cntTab==1 && sqliteIsRowid(zCol) ){
    cnt = 1;
    pExpr->iColumn = -1;
    pExpr->dataType = SQLITE_SO_NUM;
  }

  /*
  ** If the input is of the form Z (not Y.Z or X.Y.Z) then the name Z
  ** might refer to an result-set alias.  This happens, for example, when
  ** we are resolving names in the WHERE clause of the following command:
  **
  **     SELECT a+b AS x FROM table WHERE x<10;
  **
  ** In cases like this, replace pExpr with a copy of the expression that
  ** forms the result set entry ("a+b" in the example) and return immediately.
  ** Note that the expression in the result set should have already been
  ** resolved by the time the WHERE clause is resolved.
  */
  if( cnt==0 && pEList!=0 ){
    for(j=0; j<pEList->nExpr; j++){
      char *zAs = pEList->a[j].zName;
      if( zAs!=0 && sqliteStrICmp(zAs, zCol)==0 ){
        assert( pExpr->pLeft==0 && pExpr->pRight==0 );
        pExpr->op = TK_AS;
        pExpr->iColumn = j;
        pExpr->pLeft = sqliteExprDup(pEList->a[j].pExpr);
        sqliteFree(zCol);
        assert( zTab==0 && zDb==0 );
        return 0;
      }
    } 
  }

  /*
  ** If X and Y are NULL (in other words if only the column name Z is
  ** supplied) and the value of Z is enclosed in double-quotes, then
  ** Z is a string literal if it doesn't match any column names.  In that
  ** case, we need to return right away and not make any changes to
  ** pExpr.
  */
  if( cnt==0 && zTab==0 && pColumnToken->z[0]=='"' ){
    sqliteFree(zCol);
    return 0;
  }

  /*
  ** cnt==0 means there was not match.  cnt>1 means there were two or
  ** more matches.  Either way, we have an error.
  */
  if( cnt!=1 ){
    char *z = 0;
    char *zErr;
    zErr = cnt==0 ? "no such column: %s" : "ambiguous column name: %s";
    if( zDb ){
      sqliteSetString(&z, zDb, ".", zTab, ".", zCol, 0);
    }else if( zTab ){
      sqliteSetString(&z, zTab, ".", zCol, 0);
    }else{
      z = sqliteStrDup(zCol);
    }
    sqliteErrorMsg(pParse, zErr, z);
    sqliteFree(z);
  }

  /* Clean up and return
  */
  sqliteFree(zDb);
  sqliteFree(zTab);
  sqliteFree(zCol);
  sqliteExprDelete(pExpr->pLeft);
  pExpr->pLeft = 0;
  sqliteExprDelete(pExpr->pRight);
  pExpr->pRight = 0;
  pExpr->op = TK_COLUMN;
  sqliteAuthRead(pParse, pExpr, pSrcList);
  return cnt!=1;
}