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 1.78 2003/04/03 01:50:44 drh Exp $
*/
#include "sqliteInt.h"

/*
** This routine is call to handle SQL of the following forms:
**
**    insert into TABLE (IDLIST) values(EXPRLIST)

  ** 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;

    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.
    **
    ** A temp table must be used if the table being updated is also one
    ** of the tables being read by the SELECT statement.  Also use a 
    ** temp table in the case of row triggers.
    */
    if( row_triggers_exist ){
      useTempTable = 1;
    }else{
      int addr = sqliteVdbeFindOp(v, OP_OpenRead, pTab->tnum);
      useTempTable = 0;
      if( addr>0 ){
        VdbeOp *pOp = sqliteVdbeGetOp(v, addr-2);
        if( pOp->opcode==OP_Integer && pOp->p1==pTab->iDb ){
          useTempTable = 1;
        }
      }
    }

    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);

**
** Various scripts scan this source file in order to generate HTML
** documentation, headers files, or other derived files.  The formatting
** of the code in this file is, therefore, important.  See other comments
** in this file for details.  If in doubt, do not deviate from existing
** commenting and indentation practices when changing or adding code.
**
** $Id: vdbe.c,v 1.210 2003/04/03 01:50:45 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** The makefile scans this source file and creates the following
** array of string constants which are the names of all VDBE opcodes.

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

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

/*
** Return the opcode for a given address.
*/
VdbeOp *sqliteVdbeGetOp(Vdbe *p, int addr){
  assert( p->magic==VDBE_MAGIC_INIT );
  assert( addr>=0 && addr<p->nOp );
  return &p->aOp[addr];
}

/*
** 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.

*************************************************************************
** 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 1.65 2003/04/03 01:50:47 drh Exp $
*/
#ifndef _SQLITE_VDBE_H_
#define _SQLITE_VDBE_H_
#include <stdio.h>

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

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);
VdbeOp *sqliteVdbeGetOp(Vdbe*, int);
int sqliteVdbeMakeLabel(Vdbe*);
void sqliteVdbeDelete(Vdbe*);
void sqliteVdbeMakeReady(Vdbe*,sqlite_callback,void*,int);
int sqliteVdbeExec(Vdbe*);
int sqliteVdbeList(Vdbe*);
int sqliteVdbeFinalize(Vdbe*,char**);
void sqliteVdbeResolveLabel(Vdbe*, int);
int sqliteVdbeCurrentAddr(Vdbe*);
void sqliteVdbeTrace(Vdbe*,FILE*);
void sqliteVdbeCompressSpace(Vdbe*,int);

#endif

# 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.
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this file is testing the INSERT statement.
#
# $Id: insert.test,v 1.12 2003/04/03 01:50:48 drh Exp $

set testdir [file dirname $argv0]
source $testdir/tester.tcl

# Try to insert into a non-existant table.
#
do_test insert-1.1 {

do_test insert-4.7 {
  execsql {
    INSERT INTO t3 VALUES(min(1,2,3),max(1,2,3),99);
    SELECT * FROM t3 WHERE c=99;
  }
} {1 3 99}

# Test the ability to insert from a temporary table into itself.
# Ticket #275.
#
do_test insert-5.1 {
  execsql {
    CREATE TEMP TABLE t4(x);
    INSERT INTO t4 VALUES(1);
    SELECT * FROM t4;
  }
} {1}
do_test insert-5.2 {
  execsql {
    INSERT INTO t4 SELECT x+1 FROM t4;
    SELECT * FROM t4;
  }
} {1 2}
do_test insert-5.3 {
  # verify that a temporary table is used to copy t4 to t4
  set x [execsql {
    EXPLAIN INSERT INTO t4 SELECT x+2 FROM t4;
  }]
  expr {[lsearch $x OpenTemp]>0}
} {1}
do_test insert-5.4 {
  # Verify that table "test1" begins on page 3.  This should be the same
  # page number used by "t4" above.
  execsql {
    SELECT rootpage FROM sqlite_master WHERE name='test1';
  }
} {3}
do_test insert-5.5 {
  # Verify that "t4" begins on page 3.
  execsql {
    SELECT rootpage FROM sqlite_temp_master WHERE name='t4';
  }
} {3}
do_test insert-5.6 {
  # This should not use an intermediate temporary table.
  execsql {
    INSERT INTO t4 SELECT one FROM test1 WHERE three=7;
    SELECT * FROM t4
  }
} {1 2 8}
do_test insert-5.7 {
  # verify that no temporary table is used to copy test1 to t4
  set x [execsql {
    EXPLAIN INSERT INTO t4 SELECT one FROM test1;
  }]
  expr {[lsearch $x OpenTemp]>0}
} {0}


finish_test