SQLite

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle INSERT statements in SQLite.
**
** $Id: insert.c,v 1.66 2002/08/28 03:00:58 drh Exp $
*/
#include "sqliteInt.h"

/*
** This routine is call to handle SQL of the following forms:
**
**    insert into TABLE (IDLIST) values(EXPRLIST)
**    insert into TABLE (IDLIST) select
**
** The IDLIST following the table name is always optional.  If omitted,
** then a list of all columns for the table is substituted.  The IDLIST
** appears in the pColumn parameter.  pColumn is NULL if IDLIST is omitted.
**
** The pList parameter holds EXPRLIST in the first form of the INSERT
** statement above, and pSelect is NULL.  For the second form, pList is
** NULL and pSelect is a pointer to the select statement used to generate
** data for the insert.
**
** The code generated follows one of three templates.  For a simple
** select with data coming from a VALUES clause, the code executes
** once straight down through.  The template looks like this:
**
**         open write cursor to <table> and its indices
**         puts VALUES clause expressions onto the stack
**         write the resulting record into <table>
**         cleanup
**
** If the statement is of the form
**
**   INSERT INTO <table> SELECT ...
**
** And the SELECT clause does not read from <table> at any time, then
** the generated code follows this template:
**
**         goto B
**      A: setup for the SELECT
**         loop over the tables in the SELECT
**           gosub C
**         end loop
**         cleanup after the SELECT
**         goto D
**      B: open write cursor to <table> and its indices
**         goto A
**      C: insert the select result into <table>
**         return
**      D: cleanup
**
** The third template is used if the insert statement takes its
** values from a SELECT but the data is being inserted into a table
** that is also read as part of the SELECT.  In the third form,
** we have to use a intermediate table to store the results of
** the select.  The template is like this:
**
**         goto B
**      A: setup for the SELECT
**         loop over the tables in the SELECT
**           gosub C
**         end loop
**         cleanup after the SELECT
**         goto D
**      C: insert the select result into the intermediate table
**         return
**      B: open a cursor to an intermediate table
**         goto A
**      D: open write cursor to <table> and its indices
**         loop over the intermediate table
**           transfer values form intermediate table into <table>
**         end the loop
**         cleanup
*/
void sqliteInsert(
  Parse *pParse,        /* Parser context */
  Token *pTableName,    /* Name of table into which we are inserting */
  ExprList *pList,      /* List of values to be inserted */
  Select *pSelect,      /* A SELECT statement to use as the data source */
  IdList *pColumn,      /* Column names corresponding to IDLIST. */
  int onError           /* How to handle constraint errors */
){
  Table *pTab;          /* The table to insert into */
  char *zTab = 0;       /* Name of the table into which we are inserting */
  int i, j, idx;        /* Loop counters */
  Vdbe *v;              /* Generate code into this virtual machine */
  Index *pIdx;          /* For looping over indices of the table */

  int nColumn;          /* Number of columns in the data */
  int base;             /* First available cursor */
  int iCont, iBreak;    /* Beginning and end of the loop over srcTab */
  sqlite *db;           /* The main database structure */
  int openOp;           /* Opcode used to open cursors */
  int keyColumn = -1;   /* Column that is the INTEGER PRIMARY KEY */
  int endOfLoop;        /* Label for the end of the insertion loop */
  int useTempTable;     /* Store SELECT results in intermediate table */
  int srcTab;           /* Data comes from this temporary cursor if >=0 */
  int iSelectLoop;      /* Address of code that implements the SELECT */
  int iCleanup;         /* Address of the cleanup code */
  int iInsertBlock;     /* Address of the subroutine used to insert data */
  int iCntMem;          /* Memory cell used for the row counter */

  int row_triggers_exist = 0; /* True if there are FOR EACH ROW triggers */
  int newIdx = -1;

  if( pParse->nErr || sqlite_malloc_failed ) goto insert_cleanup;
  db = pParse->db;

  /* if there are row triggers, allocate a temp table for new.* references. */
  if( row_triggers_exist ){
    newIdx = pParse->nTab++;
  }

  /* Figure out how many columns of data are supplied.  If the data
  ** is coming from a SELECT statement, then this step also generates
  ** all the code to implement the SELECT statement and invoke a subroutine
  ** to process each row of the result. (Template 2.) If the SELECT
  ** statement uses the the table that is being inserted into, then the
  ** subroutine is also coded here.  That subroutine stores the SELECT
  ** results in a temporary table. (Template 3.)

  */
  if( pSelect ){
    /* Data is coming from a SELECT.  Generate code to implement that SELECT
    */
    int rc, iInitCode;

    int opCode;
    iInitCode = sqliteVdbeAddOp(v, OP_Goto, 0, 0);
    iSelectLoop = sqliteVdbeCurrentAddr(v);
    iInsertBlock = sqliteVdbeMakeLabel(v);
    rc = sqliteSelect(pParse, pSelect, SRT_Subroutine, iInsertBlock, 0,0,0);
    if( rc || pParse->nErr || sqlite_malloc_failed ) goto insert_cleanup;
    iCleanup = sqliteVdbeMakeLabel(v);
    sqliteVdbeAddOp(v, OP_Goto, 0, iCleanup);
    assert( pSelect->pEList );
    nColumn = pSelect->pEList->nExpr;

    /* Set useTempTable to TRUE if the result of the SELECT statement
    ** should be written into a temporary table.  Set to FALSE if each
    ** row of the SELECT can be written directly into the result table.
    */
    opCode = pTab->isTemp ? OP_OpenTemp : OP_Open;
    useTempTable = row_triggers_exist || sqliteVdbeFindOp(v,opCode,pTab->tnum);

    if( useTempTable ){
      /* Generate the subroutine that SELECT calls to process each row of
      ** the result.  Store the result in a temporary table
      */
      srcTab = pParse->nTab++;
      sqliteVdbeResolveLabel(v, iInsertBlock);
      sqliteVdbeAddOp(v, OP_MakeRecord, nColumn, 0);
      sqliteVdbeAddOp(v, OP_NewRecno, srcTab, 0);
      sqliteVdbeAddOp(v, OP_Pull, 1, 0);
      sqliteVdbeAddOp(v, OP_PutIntKey, srcTab, 0);
      sqliteVdbeAddOp(v, OP_Return, 0, 0);

      /* The following code runs first because the GOTO at the very top
      ** of the program jumps to it.  Create the temporary table, then jump
      ** back up and execute the SELECT code above.
      */
      sqliteVdbeChangeP2(v, iInitCode, sqliteVdbeCurrentAddr(v));
      sqliteVdbeAddOp(v, OP_OpenTemp, srcTab, 0);
      sqliteVdbeAddOp(v, OP_Goto, 0, iSelectLoop);
      sqliteVdbeResolveLabel(v, iCleanup);
    }else{
      sqliteVdbeChangeP2(v, iInitCode, sqliteVdbeCurrentAddr(v));
    }
  }else{
    /* This is the case if the data for the INSERT is coming from a VALUES
    ** clause
    */
    SrcList dummy;
    assert( pList!=0 );
    srcTab = -1;
    useTempTable = 0;
    assert( pList );
    nColumn = pList->nExpr;
    dummy.nSrc = 0;
    for(i=0; i<nColumn; i++){
      if( sqliteExprResolveIds(pParse, 0, &dummy, 0, pList->a[i].pExpr) ){
        goto insert_cleanup;
      }

  ** 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_OpenTemp, 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;
    openOp = pTab->isTemp ? OP_OpenWrAux : OP_OpenWrite;
    sqliteVdbeAddOp(v, openOp, base, pTab->tnum);
    sqliteVdbeChangeP3(v, -1, pTab->zName, P3_STATIC);
    for(idx=1, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, idx++){
      sqliteVdbeAddOp(v, openOp, idx+base, pIdx->tnum);
      sqliteVdbeChangeP3(v, -1, pIdx->zName, P3_STATIC);
    }
    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);
  }

  endOfLoop = sqliteVdbeMakeLabel(v);
  if( row_triggers_exist ){

    /* build the new.* reference row */
    sqliteVdbeAddOp(v, OP_Integer, 13, 0);
    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 ){
        sqliteVdbeAddOp(v, OP_String, 0, 0);
        sqliteVdbeChangeP3(v, -1, 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);
    sqliteVdbeAddOp(v, OP_Rewind, newIdx, 0);

  /* 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( !pTab->pSelect ){
    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);

        for(j=0; j<pColumn->nId; j++){
          if( pColumn->a[j].idx==i ) break;
        }
      }
      if( pColumn && j>=pColumn->nId ){
        sqliteVdbeAddOp(v, OP_String, 0, 0);
        sqliteVdbeChangeP3(v, -1, 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, 0,0,0,onError,endOfLoop);
    sqliteCompleteInsertion(pParse, pTab, base, 0,0,0);

    /* 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( !pTab->pSelect ){
      sqliteVdbeAddOp(v, OP_Close, base, 0);

      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);
    }
  }

  sqliteEndWriteOperation(pParse);

  /*
  ** Return the number of rows inserted.
  */
  if( db->flags & SQLITE_CountRows ){
    sqliteVdbeAddOp(v, OP_ColumnCount, 1, 0);
    sqliteVdbeAddOp(v, OP_ColumnName, 0, 0);
    sqliteVdbeChangeP3(v, -1, "rows inserted", P3_STATIC);
    sqliteVdbeAddOp(v, OP_MemLoad, iCntMem, 0);
    sqliteVdbeAddOp(v, OP_Callback, 1, 0);
  }

insert_cleanup:
  if( pList ) sqliteExprListDelete(pList);
  if( pSelect ) sqliteSelectDelete(pSelect);
  if ( zTab ) sqliteFree(zTab);

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle SELECT statements in SQLite.
**
** $Id: select.c,v 1.111 2002/08/28 03:00:59 drh Exp $
*/
#include "sqliteInt.h"

/*
** Allocate a new Select structure and return a pointer to that
** structure.
*/

        pushOntoSorter(pParse, v, pOrderBy);
      }else{
        assert( eDest==SRT_Callback );
        sqliteVdbeAddOp(v, OP_Callback, nColumn, 0);
      }
      break;
    }

    /* Invoke a subroutine to handle the results.  The subroutine itself
    ** is responsible for popping the results off of the stack.
    */
    case SRT_Subroutine: {
      sqliteVdbeAddOp(v, OP_Gosub, 0, iParm);
      break;
    }

    /* Discard the results.  This is used for SELECT statements inside
    ** the body of a TRIGGER.  The purpose of such selects is to call
    ** user-defined functions that have side effects.  We do not care
    ** about the actual results of the select.
    */
    default: {

** "p" points to the right-most of the two queries.  The results should
** be stored in eDest with parameter iParm.
*/
static int multiSelect(Parse *pParse, Select *p, int eDest, int iParm){
  int rc;             /* Success code from a subroutine */
  Select *pPrior;     /* Another SELECT immediately to our left */
  Vdbe *v;            /* Generate code to this VDBE */


  /* Make sure there is no ORDER BY clause on prior SELECTs.  Only the 
  ** last SELECT in the series may have an ORDER BY.
  */
  if( p==0 || p->pPrior==0 ) return 1;
  pPrior = p->pPrior;
  if( pPrior->pOrderBy ){

  if( eDest==SRT_TempTable ){
    sqliteVdbeAddOp(v, OP_OpenTemp, iParm, 0);
    eDest = SRT_Table;
  }

  /* Generate code for the left and right SELECT statements.
  */

  switch( p->op ){
    case TK_ALL: {
      if( p->pOrderBy==0 ){
        rc = sqliteSelect(pParse, pPrior, eDest, iParm, 0, 0, 0);
        if( rc ) return rc;
        p->pPrior = 0;
        rc = sqliteSelect(pParse, p, eDest, iParm, 0, 0, 0);

  assert( p->pEList && pPrior->pEList );
  if( p->pEList->nExpr!=pPrior->pEList->nExpr ){
    sqliteSetString(&pParse->zErrMsg, "SELECTs to the left and right of ",
      selectOpName(p->op), " do not have the same number of result columns", 0);
    pParse->nErr++;
    return 1;
  }

  return 0;
}

/*
** Recursively scan through an expression tree.  For every reference
** to a column in table number iFrom, change that reference to the
** same column in table number iTo.

  */
  rc = 0;

  /* Control jumps to here if an error is encountered above, or upon
  ** successful coding of the SELECT.
  */
select_end:
  /* pParse->nTab = base; */
  sqliteAggregateInfoReset(pParse);
  return rc;
}

/*
** 2001 September 15
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** Internal interface definitions for SQLite.
**
** @(#) $Id: sqliteInt.h,v 1.144 2002/08/28 03:00:59 drh Exp $
*/
#include "sqlite.h"
#include "hash.h"
#include "vdbe.h"
#include "parse.h"
#include "btree.h"
#include <stdio.h>

#define SRT_Set          3  /* Store result as unique keys in a table */
#define SRT_Union        5  /* Store result as keys in a table */
#define SRT_Except       6  /* Remove result from a UNION table */
#define SRT_Table        7  /* Store result as data with a unique key */
#define SRT_TempTable    8  /* Store result in a trasient table */
#define SRT_Discard      9  /* Do not save the results anywhere */
#define SRT_Sorter      10  /* Store results in the sorter */
#define SRT_Subroutine  11  /* Call a subroutine to handle results */

/*
** When a SELECT uses aggregate functions (like "count(*)" or "avg(f1)")
** we have to do some additional analysis of expressions.  An instance
** of the following structure holds information about a single subexpression
** somewhere in the SELECT statement.  An array of these structures holds
** all the information we need to generate code for aggregate

** type to the other occurs as necessary.
** 
** Most of the code in this file is taken up by the sqliteVdbeExec()
** function which does the work of interpreting a VDBE program.
** But other routines are also provided to help in building up
** a program instruction by instruction.
**
** $Id: vdbe.c,v 1.173 2002/08/28 03:01:00 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** The following global variable is incremented every time a cursor
** moves, either by the OP_MoveTo or the OP_Next opcode.  The test

    }else{
      z[j++] = z[i++];
    }
  }
  while( j>0 && isspace(z[j-1]) ){ j--; }
  z[j] = 0;
}

/*
** Search for the current program for the given opcode and P2
** value.  Return 1 if found and 0 if not found.
*/
int sqliteVdbeFindOp(Vdbe *p, int op, int p2){
  int i;
  for(i=0; i<p->nOp; i++){
    if( p->aOp[i].opcode==op && p->aOp[i].p2==p2 ) return 1;
  }
  return 0;
}

/*
** The following group or routines are employed by installable functions
** to return their results.
**
** The sqlite_set_result_string() routine can be used to return a string
** value or to return a NULL.  To return a NULL, pass in NULL for zResult.

        break;
      }
    }
    sqliteRollbackInternalChanges(db);
  }
  sqliteBtreeCommitCkpt(pBt);
  if( db->pBeTemp ) sqliteBtreeCommitCkpt(db->pBeTemp);
  assert( p->tos<pc || sqlite_malloc_failed==1 );
  return rc;

  /* Jump to here if a malloc() fails.  It's hard to get a malloc()
  ** to fail on a modern VM computer, so this code is untested.
  */
no_mem:
  sqliteSetString(pzErrMsg, "out of memory", 0);

*************************************************************************
** Header file for the Virtual DataBase Engine (VDBE)
**
** This header defines the interface to the virtual database engine
** or VDBE.  The VDBE implements an abstract machine that runs a
** simple program to access and modify the underlying database.
**
** $Id: vdbe.h,v 1.59 2002/08/28 03:01:01 drh Exp $
*/
#ifndef _SQLITE_VDBE_H_
#define _SQLITE_VDBE_H_
#include <stdio.h>

/*
** A single VDBE is an opaque structure named "Vdbe".  Only routines

void sqliteVdbeCreateCallback(Vdbe*, int*);
int sqliteVdbeAddOp(Vdbe*,int,int,int);
int sqliteVdbeAddOpList(Vdbe*, int nOp, VdbeOp const *aOp);
void sqliteVdbeChangeP1(Vdbe*, int addr, int P1);
void sqliteVdbeChangeP2(Vdbe*, int addr, int P2);
void sqliteVdbeChangeP3(Vdbe*, int addr, const char *zP1, int N);
void sqliteVdbeDequoteP3(Vdbe*, int addr);
int sqliteVdbeFindOp(Vdbe*, int, int);
int sqliteVdbeMakeLabel(Vdbe*);
void sqliteVdbeDelete(Vdbe*);
int sqliteVdbeOpcode(const char *zName);
int sqliteVdbeExec(Vdbe*,sqlite_callback,void*,char**,void*,
                   int(*)(void*,const char*,int));
int sqliteVdbeList(Vdbe*,sqlite_callback,void*,char**);
void sqliteVdbeResolveLabel(Vdbe*, int);
int sqliteVdbeCurrentAddr(Vdbe*);
void sqliteVdbeTrace(Vdbe*,FILE*);
void sqliteVdbeCompressSpace(Vdbe*,int);

#endif

**    May you share freely, never taking more than you give.
**
*************************************************************************
** This module contains C code that generates VDBE code used to process
** the WHERE clause of SQL statements.  Also found here are subroutines
** to generate VDBE code to evaluate expressions.
**
** $Id: where.c,v 1.64 2002/08/28 03:01:01 drh Exp $
*/
#include "sqliteInt.h"

/*
** The query generator uses an array of instances of this structure to
** help it analyze the subexpressions of the WHERE clause.  Each WHERE
** clause subexpression is separated from the others by an AND operator.

    if( pTabList->a[i].pTab->isTransient ) continue;
    pLevel = &pWInfo->a[i];
    sqliteVdbeAddOp(v, OP_Close, base+i, 0);
    if( pLevel->pIdx!=0 ){
      sqliteVdbeAddOp(v, OP_Close, pLevel->iCur, 0);
    }
  }
#if 0  /* Never reuse a cursor */
  if( pWInfo->pParse->nTab==pWInfo->peakNTab ){
    pWInfo->pParse->nTab = pWInfo->savedNTab;
  }
#endif
  sqliteFree(pWInfo);
  return;
}