insert.c

sqlite数据库管理系统开放源码

  /* If there is no IDLIST term but the table has an integer primary
  ** key, the set the keyColumn variable to the primary key column index
  ** in the original table definition.
  */
  if( pColumn==0 ){
    keyColumn = pTab->iPKey;
  }

  /* Open the temp table for FOR EACH ROW triggers
  */
  if( row_triggers_exist ){
    sqliteVdbeAddOp(v, OP_OpenPseudo, newIdx, 0);
  }
    
  /* Initialize the count of rows to be inserted
  */
  if( db->flags & SQLITE_CountRows ){
    iCntMem = pParse->nMem++;
    sqliteVdbeAddOp(v, OP_Integer, 0, 0);
    sqliteVdbeAddOp(v, OP_MemStore, iCntMem, 1);
  }

  /* Open tables and indices if there are no row triggers */
  if( !row_triggers_exist ){
    base = pParse->nTab;
    idx = sqliteOpenTableAndIndices(pParse, pTab, base);
    pParse->nTab += idx;
  }

  /* If the data source is a temporary table, then we have to create
  ** a loop because there might be multiple rows of data.  If the data
  ** source is a subroutine call from the SELECT statement, then we need
  ** to launch the SELECT statement processing.
  */
  if( useTempTable ){
    iBreak = sqliteVdbeMakeLabel(v);
    sqliteVdbeAddOp(v, OP_Rewind, srcTab, iBreak);
    iCont = sqliteVdbeCurrentAddr(v);
  }else if( pSelect ){
    sqliteVdbeAddOp(v, OP_Goto, 0, iSelectLoop);
    sqliteVdbeResolveLabel(v, iInsertBlock);
  }

  /* Run the BEFORE and INSTEAD OF triggers, if there are any
  */
  endOfLoop = sqliteVdbeMakeLabel(v);
  if( before_triggers ){

    /* build the NEW.* reference row.  Note that if there is an INTEGER
    ** PRIMARY KEY into which a NULL is being inserted, that NULL will be
    ** translated into a unique ID for the row.  But on a BEFORE trigger,
    ** we do not know what the unique ID will be (because the insert has
    ** not happened yet) so we substitute a rowid of -1
    */
    if( keyColumn<0 ){
      sqliteVdbeAddOp(v, OP_Integer, -1, 0);
    }else if( useTempTable ){
      sqliteVdbeAddOp(v, OP_Column, srcTab, keyColumn);
    }else if( pSelect ){
      sqliteVdbeAddOp(v, OP_Dup, nColumn - keyColumn - 1, 1);
    }else{
      sqliteExprCode(pParse, pList->a[keyColumn].pExpr);
      sqliteVdbeAddOp(v, OP_NotNull, -1, sqliteVdbeCurrentAddr(v)+3);
      sqliteVdbeAddOp(v, OP_Pop, 1, 0);
      sqliteVdbeAddOp(v, OP_Integer, -1, 0);
      sqliteVdbeAddOp(v, OP_MustBeInt, 0, 0);
    }

    /* Create the new column data
    */
    for(i=0; i<pTab->nCol; i++){
      if( pColumn==0 ){
        j = i;
      }else{
        for(j=0; j<pColumn->nId; j++){
          if( pColumn->a[j].idx==i ) break;
        }
      }
      if( pColumn && j>=pColumn->nId ){
        sqliteVdbeOp3(v, OP_String, 0, 0, pTab->aCol[i].zDflt, P3_STATIC);
      }else if( useTempTable ){
        sqliteVdbeAddOp(v, OP_Column, srcTab, j); 
      }else if( pSelect ){
        sqliteVdbeAddOp(v, OP_Dup, nColumn-j-1, 1);
      }else{
        sqliteExprCode(pParse, pList->a[j].pExpr);
      }
    }
    sqliteVdbeAddOp(v, OP_MakeRecord, pTab->nCol, 0);
    sqliteVdbeAddOp(v, OP_PutIntKey, newIdx, 0);

    /* Fire BEFORE or INSTEAD OF triggers */
    if( sqliteCodeRowTrigger(pParse, TK_INSERT, 0, TK_BEFORE, pTab, 
        newIdx, -1, onError, endOfLoop) ){
      goto insert_cleanup;
    }
  }

  /* If any triggers exists, the opening of tables and indices is deferred
  ** until now.
  */
  if( row_triggers_exist && !isView ){
    base = pParse->nTab;
    idx = sqliteOpenTableAndIndices(pParse, pTab, base);
    pParse->nTab += idx;
  }

  /* Push the record number for the new entry onto the stack.  The
  ** record number is a randomly generate integer created by NewRecno
  ** except when the table has an INTEGER PRIMARY KEY column, in which
  ** case the record number is the same as that column. 
  */
  if( !isView ){
    if( keyColumn>=0 ){
      if( useTempTable ){
        sqliteVdbeAddOp(v, OP_Column, srcTab, keyColumn);
      }else if( pSelect ){
        sqliteVdbeAddOp(v, OP_Dup, nColumn - keyColumn - 1, 1);
      }else{
        sqliteExprCode(pParse, pList->a[keyColumn].pExpr);
      }
      /* If the PRIMARY KEY expression is NULL, then use OP_NewRecno
      ** to generate a unique primary key value.
      */
      sqliteVdbeAddOp(v, OP_NotNull, -1, sqliteVdbeCurrentAddr(v)+3);
      sqliteVdbeAddOp(v, OP_Pop, 1, 0);
      sqliteVdbeAddOp(v, OP_NewRecno, base, 0);
      sqliteVdbeAddOp(v, OP_MustBeInt, 0, 0);
    }else{
      sqliteVdbeAddOp(v, OP_NewRecno, base, 0);
    }

    /* Push onto the stack, data for all columns of the new entry, beginning
    ** with the first column.
    */
    for(i=0; i<pTab->nCol; i++){
      if( i==pTab->iPKey ){
        /* The value of the INTEGER PRIMARY KEY column is always a NULL.
        ** Whenever this column is read, the record number will be substituted
        ** in its place.  So will fill this column with a NULL to avoid
        ** taking up data space with information that will never be used. */
        sqliteVdbeAddOp(v, OP_String, 0, 0);
        continue;
      }
      if( pColumn==0 ){
        j = i;
      }else{
        for(j=0; j<pColumn->nId; j++){
          if( pColumn->a[j].idx==i ) break;
        }
      }
      if( pColumn && j>=pColumn->nId ){
        sqliteVdbeOp3(v, OP_String, 0, 0, pTab->aCol[i].zDflt, P3_STATIC);
      }else if( useTempTable ){
        sqliteVdbeAddOp(v, OP_Column, srcTab, j); 
      }else if( pSelect ){
        sqliteVdbeAddOp(v, OP_Dup, i+nColumn-j, 1);
      }else{
        sqliteExprCode(pParse, pList->a[j].pExpr);
      }
    }

    /* Generate code to check constraints and generate index keys and
    ** do the insertion.
    */
    sqliteGenerateConstraintChecks(pParse, pTab, base, 0, keyColumn>=0,
                                   0, onError, endOfLoop);
    sqliteCompleteInsertion(pParse, pTab, base, 0,0,0,
                            after_triggers ? newIdx : -1);
  }

  /* Update the count of rows that are inserted
  */
  if( (db->flags & SQLITE_CountRows)!=0 ){
    sqliteVdbeAddOp(v, OP_MemIncr, iCntMem, 0);
  }

  if( row_triggers_exist ){
    /* Close all tables opened */
    if( !isView ){
      sqliteVdbeAddOp(v, OP_Close, base, 0);
      for(idx=1, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, idx++){
        sqliteVdbeAddOp(v, OP_Close, idx+base, 0);
      }
    }

    /* Code AFTER triggers */
    if( sqliteCodeRowTrigger(pParse, TK_INSERT, 0, TK_AFTER, pTab, newIdx, -1, 
          onError, endOfLoop) ){
      goto insert_cleanup;
    }
  }

  /* The bottom of the loop, if the data source is a SELECT statement
  */
  sqliteVdbeResolveLabel(v, endOfLoop);
  if( useTempTable ){
    sqliteVdbeAddOp(v, OP_Next, srcTab, iCont);
    sqliteVdbeResolveLabel(v, iBreak);
    sqliteVdbeAddOp(v, OP_Close, srcTab, 0);
  }else if( pSelect ){
    sqliteVdbeAddOp(v, OP_Pop, nColumn, 0);
    sqliteVdbeAddOp(v, OP_Return, 0, 0);
    sqliteVdbeResolveLabel(v, iCleanup);
  }

  if( !row_triggers_exist ){
    /* Close all tables opened */
    sqliteVdbeAddOp(v, OP_Close, base, 0);
    for(idx=1, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, idx++){
      sqliteVdbeAddOp(v, OP_Close, idx+base, 0);
    }
  }

  sqliteVdbeAddOp(v, OP_SetCounts, 0, 0);
  sqliteEndWriteOperation(pParse);

  /*
  ** Return the number of rows inserted.
  */
  if( db->flags & SQLITE_CountRows ){
    sqliteVdbeOp3(v, OP_ColumnName, 0, 1, "rows inserted", P3_STATIC);
    sqliteVdbeAddOp(v, OP_MemLoad, iCntMem, 0);
    sqliteVdbeAddOp(v, OP_Callback, 1, 0);
  }

insert_cleanup:
  sqliteSrcListDelete(pTabList);
  if( pList ) sqliteExprListDelete(pList);
  if( pSelect ) sqliteSelectDelete(pSelect);
  sqliteIdListDelete(pColumn);
}

/*
** Generate code to do a constraint check prior to an INSERT or an UPDATE.
**
** When this routine is called, the stack contains (from bottom to top)
** the following values:
**
**    1.  The recno of the row to be updated before the update.  This
**        value is omitted unless we are doing an UPDATE that involves a
**        change to the record number.
**
**    2.  The recno of the row after the update.
**
**    3.  The data in the first column of the entry after the update.
**
**    i.  Data from middle columns...
**
**    N.  The data in the last column of the entry after the update.
**
** The old recno shown as entry (1) above is omitted unless both isUpdate
** and recnoChng are 1.  isUpdate is true for UPDATEs and false for
** INSERTs and recnoChng is true if the record number is being changed.
**
** The code generated by this routine pushes additional entries onto
** the stack which are the keys for new index entries for the new record.
** The order of index keys is the same as the order of the indices on
** the pTable->pIndex list.  A key is only created for index i if 
** aIdxUsed!=0 and aIdxUsed[i]!=0.
**
** This routine also generates code to check constraints.  NOT NULL,
** CHECK, and UNIQUE constraints are all checked.  If a constraint fails,
** then the appropriate action is performed.  There are five possible
** actions: ROLLBACK, ABORT, FAIL, REPLACE, and IGNORE.
**
**  Constraint type  Action       What Happens
**  ---------------  ----------   ----------------------------------------
**  any              ROLLBACK     The current transaction is rolled back and
**                                sqlite_exec() returns immediately with a
**                                return code of SQLITE_CONSTRAINT.
**
**  any              ABORT        Back out changes from the current command
**                                only (do not do a complete rollback) then
**                                cause sqlite_exec() to return immediately
**                                with SQLITE_CONSTRAINT.
**
**  any              FAIL         Sqlite_exec() returns immediately with a
**                                return code of SQLITE_CONSTRAINT.  The
**                                transaction is not rolled back and any
**                                prior changes are retained.
**
**  any              IGNORE       The record number and data is popped from
**                                the stack and there is an immediate jump
**                                to label ignoreDest.
**
**  NOT NULL         REPLACE      The NULL value is replace by the default
**                                value for that column.  If the default value
**                                is NULL, the action is the same as ABORT.
**
**  UNIQUE           REPLACE      The other row that conflicts with the row
**                                being inserted is removed.
**
**  CHECK            REPLACE      Illegal.  The results in an exception.
**
** Which action to take is determined by the overrideError parameter.
** Or if overrideError==OE_Default, then the pParse->onError parameter
** is used.  Or if pParse->onError==OE_Default then the onError value
** for the constraint is used.
**
** The calling routine must open a read/write cursor for pTab with
** cursor number "base".  All indices of pTab must also have open
** read/write cursors with cursor number base+i for the i-th cursor.
** Except, if there is no possibility of a REPLACE action then
** cursors do not need to be open for indices where aIdxUsed[i]==0.
**
** If the isUpdate flag is true, it means that the "base" cursor is