SQLite

2.2.1

/*
** 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.
**
*************************************************************************
** $Id: btree.c,v 1.46 2002/01/04 03:09:29 drh Exp $
**
** This file implements a external (disk-based) database using BTrees.
** For a detailed discussion of BTrees, refer to
**
**     Donald E. Knuth, THE ART OF COMPUTER PROGRAMMING, Volume 3:
**     "Sorting And Searching", pages 473-480. Addison-Wesley
**     Publishing Company, Reading, Massachusetts.

** Attempt to start a new transaction.
**
** A transaction must be started before attempting any changes
** to the database.  None of the following routines will work
** unless a transaction is started first:
**
**      sqliteBtreeCreateTable()
**      sqliteBtreeCreateIndex()
**      sqliteBtreeClearTable()
**      sqliteBtreeDropTable()
**      sqliteBtreeInsert()
**      sqliteBtreeDelete()
**      sqliteBtreeUpdateMeta()
*/
int sqliteBtreeBeginTrans(Btree *pBt){

    }
    rc = balance(pCur->pBt, pPage, pCur);
  }
  return rc;
}

/*
** Create a new BTree table.  Write into *piTable the page
** number for the root page of the new table.
**
** In the current implementation, BTree tables and BTree indices are the 
** the same.  But in the future, we may change this so that BTree tables
** are restricted to having a 4-byte integer key and arbitrary data and
** BTree indices are restricted to having an arbitrary key and no data.
*/
int sqliteBtreeCreateTable(Btree *pBt, int *piTable){
  MemPage *pRoot;
  Pgno pgnoRoot;
  int rc;
  if( !pBt->inTrans ){
    return SQLITE_ERROR;  /* Must start a transaction first */
  }
  rc = allocatePage(pBt, &pRoot, &pgnoRoot);
  if( rc ) return rc;
  assert( sqlitepager_iswriteable(pRoot) );
  zeroPage(pRoot);
  sqlitepager_unref(pRoot);
  *piTable = (int)pgnoRoot;
  return SQLITE_OK;
}

/*
** Create a new BTree index.  Write into *piTable the page
** number for the root page of the new index.
**
** In the current implementation, BTree tables and BTree indices are the 
** the same.  But in the future, we may change this so that BTree tables
** are restricted to having a 4-byte integer key and arbitrary data and
** BTree indices are restricted to having an arbitrary key and no data.
*/
int sqliteBtreeCreateIndex(Btree *pBt, int *piIndex){
  MemPage *pRoot;
  Pgno pgnoRoot;
  int rc;
  if( !pBt->inTrans ){
    return SQLITE_ERROR;  /* Must start a transaction first */
  }
  rc = allocatePage(pBt, &pRoot, &pgnoRoot);
  if( rc ) return rc;
  assert( sqlitepager_iswriteable(pRoot) );
  zeroPage(pRoot);
  sqlitepager_unref(pRoot);
  *piIndex = (int)pgnoRoot;
  return SQLITE_OK;
}

/*
** Erase the given database page and all its children.  Return
** the page to the freelist.
*/
static int clearDatabasePage(Btree *pBt, Pgno pgno, int freePageFlag){
  MemPage *pPage;

**    May you share freely, never taking more than you give.
**
*************************************************************************
** This header file defines the interface that the sqlite B-Tree file
** subsystem.  See comments in the source code for a detailed description
** of what each interface routine does.
**
** @(#) $Id: btree.h,v 1.19 2002/01/04 03:09:30 drh Exp $
*/
#ifndef _BTREE_H_
#define _BTREE_H_

typedef struct Btree Btree;
typedef struct BtCursor BtCursor;

int sqliteBtreeOpen(const char *zFilename, int mode, int nPg, Btree **ppBtree);
int sqliteBtreeClose(Btree*);
int sqliteBtreeSetCacheSize(Btree*, int);

int sqliteBtreeBeginTrans(Btree*);
int sqliteBtreeCommit(Btree*);
int sqliteBtreeRollback(Btree*);

int sqliteBtreeCreateTable(Btree*, int*);
int sqliteBtreeCreateIndex(Btree*, int*);
int sqliteBtreeDropTable(Btree*, int);
int sqliteBtreeClearTable(Btree*, int);

int sqliteBtreeCursor(Btree*, int iTable, int wrFlag, BtCursor **ppCur);
int sqliteBtreeMoveto(BtCursor*, const void *pKey, int nKey, int *pRes);
int sqliteBtreeDelete(BtCursor*);
int sqliteBtreeInsert(BtCursor*, const void *pKey, int nKey,

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains routines used for analyzing expressions and
** for generating VDBE code that evaluates expressions in SQLite.
**
** $Id: expr.c,v 1.36 2002/01/04 03:09:30 drh Exp $
*/
#include "sqliteInt.h"

/*
** Walk an expression tree.  Return 1 if the expression is constant
** and 0 if it involves variables.
*/

      if( pExpr->pSelect ){
        /* Case 1:     expr IN (SELECT ...)
        **
        ** Generate code to write the results of the select into a temporary
        ** table.  The cursor number of the temporary table has already
        ** been put in iTable by sqliteExprResolveInSelect().
        */
        sqliteVdbeAddOp(v, OP_OpenTemp, pExpr->iTable, 1);
        if( sqliteSelect(pParse, pExpr->pSelect, SRT_Set, pExpr->iTable) );
      }else if( pExpr->pList ){
        /* Case 2:     expr IN (exprlist)
        **
        ** Create a set to put the exprlist values in.  The Set id is stored
        ** in iTable.
        */

**    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 1.31 2002/01/04 03:09:30 drh Exp $
*/
#include "sqliteInt.h"

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

  if( (db->flags & SQLITE_InTrans)==0 ){
    sqliteVdbeAddOp(v, OP_Transaction, 0, 0);
    sqliteVdbeAddOp(v, OP_VerifyCookie, db->schema_cookie, 0);
    pParse->schemaVerified = 1;
  }

  /* Figure out how many columns of data are supplied.  If the data
  ** is coming from a SELECT statement, then this step has to generate
  ** all the code to implement the SELECT statement and leave the data
  ** in a temporary table.  If data is coming from an expression list,
  ** then we just have to count the number of expressions.
  */
  if( pSelect ){
    int rc;
    srcTab = pParse->nTab++;

**    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 1.53 2002/01/04 03:09:30 drh Exp $
*/
#include "sqliteInt.h"

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

        */
        unionTab = pParse->nTab++;
        if( p->pOrderBy 
        && matchOrderbyToColumn(pParse, p, p->pOrderBy, unionTab, 1) ){
          return 1;
        }
        if( p->op!=TK_ALL ){
          sqliteVdbeAddOp(v, OP_OpenTemp, unionTab, 1);
          sqliteVdbeAddOp(v, OP_KeyAsData, unionTab, 1);
        }else{
          sqliteVdbeAddOp(v, OP_OpenTemp, unionTab, 0);
        }
      }

      /* Code the SELECT statements to our left

      ** by allocating the tables we will need.
      */
      tab1 = pParse->nTab++;
      tab2 = pParse->nTab++;
      if( p->pOrderBy && matchOrderbyToColumn(pParse,p,p->pOrderBy,tab1,1) ){
        return 1;
      }
      sqliteVdbeAddOp(v, OP_OpenTemp, tab1, 1);
      sqliteVdbeAddOp(v, OP_KeyAsData, tab1, 1);

      /* Code the SELECTs to our left into temporary table "tab1".
      */
      rc = sqliteSelect(pParse, pPrior, SRT_Union, tab1);
      if( rc ) return rc;

      /* Code the current SELECT into temporary table "tab2"
      */
      sqliteVdbeAddOp(v, OP_OpenTemp, tab2, 1);
      sqliteVdbeAddOp(v, OP_KeyAsData, tab2, 1);
      p->pPrior = 0;
      rc = sqliteSelect(pParse, p, SRT_Union, tab2);
      p->pPrior = pPrior;
      if( rc ) return rc;

      /* Generate code to take the intersection of the two temporary

    sqliteVdbeAddOp(v, OP_String, 0, 0);
    sqliteVdbeAddOp(v, OP_MemStore, iParm, 1);
  }

  /* Begin the database scan
  */
  if( isDistinct ){
    sqliteVdbeAddOp(v, OP_OpenTemp, distinct, 1);
  }
  pWInfo = sqliteWhereBegin(pParse, pTabList, pWhere, 0);
  if( pWInfo==0 ) return 1;

  /* Use the standard inner loop if we are not dealing with
  ** aggregates
  */

** 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 1.104 2002/01/04 03:09:30 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

        goto abort_due_to_error;
      }
    }
  }while( busy );
  break;
}

/* Opcode: OpenTemp P1 P2 *
**
** Open a new cursor that points to a table or index in a temporary
** database file.  The temporary file is opened read/write even if 
** the main database is read-only.  The temporary file is deleted
** when the cursor is closed.
**
** The cursor points to a BTree table if P2==0 and to a BTree index
** if P2==1.  A BTree table must have an integer key and can have arbitrary
** data.  A BTree index has no data but can have an arbitrary key.
**
** This opcode is used for tables that exist for the duration of a single
** SQL statement only.  Tables created using CREATE TEMPORARY TABLE
** are opened using OP_OpenAux or OP_OpenWrAux.  "Temporary" in the
** context of this opcode means for the duration of a single SQL statement
** whereas "Temporary" in the context of CREATE TABLE means for the duration
** of the connection to the database.  Same word; different meanings.

    p->nCursor = i+1;
  }
  pCx = &p->aCsr[i];
  cleanupCursor(pCx);
  memset(pCx, 0, sizeof(*pCx));
  rc = sqliteBtreeOpen(0, 0, TEMP_PAGES, &pCx->pBt);
  if( rc==SQLITE_OK ){
    rc = sqliteBtreeBeginTrans(pCx->pBt);
  }
  if( rc==SQLITE_OK ){
    if( pOp->p2 ){
      int pgno;
      rc = sqliteBtreeCreateIndex(pCx->pBt, &pgno);
      if( rc==SQLITE_OK ){
        rc = sqliteBtreeCursor(pCx->pBt, pgno, 1, &pCx->pCursor);
      }
    }else{
      rc = sqliteBtreeCursor(pCx->pBt, 2, 1, &pCx->pCursor);
    }
  }
  break;
}

/* Opcode: Close P1 * *
**
** Close a cursor previously opened as P1.  If P1 is not

** for the root page of the new table onto the stack.
**
** The root page number is also written to a memory location that P3
** points to.  This is the mechanism is used to write the root page
** number into the parser's internal data structures that describe the
** new table.
**
** The difference between a table and an index is this:  A table must
** have a 4-byte integer key and can have arbitrary data.  An index
** has an arbitrary key but no data.
**
** See also: CreateIndex
*/
/* Opcode: CreateIndex * P2 P3
**
** Allocate a new index in the main database file if P2==0 or in the
** auxiliary database file if P2==1.  Push the page number of the
** root page of the new index onto the stack.
**
** See documentation on OP_CreateTable for additional information.
*/
case OP_CreateIndex:
case OP_CreateTable: {
  int i = ++p->tos;
  int pgno;
  VERIFY( if( NeedStack(p, p->tos) ) goto no_mem; )
  assert( pOp->p3!=0 && pOp->p3type==P3_POINTER );
  if( pOp->opcode==OP_CreateTable ){
    rc = sqliteBtreeCreateTable(pOp->p2 ? db->pBeTemp : pBt, &pgno);
  }else{
    rc = sqliteBtreeCreateIndex(pOp->p2 ? db->pBeTemp : pBt, &pgno);
  }
  if( rc==SQLITE_OK ){
    aStack[i].i = pgno;
    aStack[i].flags = STK_Int;
    *(u32*)pOp->p3 = pgno;
    pOp->p3 = 0;
  }
  break;

**    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 1.30 2002/01/04 03:09:30 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.

      }
      aExpr[k].p = 0;
      brk = pLevel->brk = sqliteVdbeMakeLabel(v);
      cont = pLevel->cont = brk;
      sqliteVdbeAddOp(v, OP_MustBeInt, 0, brk);
      if( i==pTabList->nId-1 && pushKey ){
        haveKey = 1;
        sqliteVdbeAddOp(v, OP_Distinct, base+idx, brk);
      }else{
        sqliteVdbeAddOp(v, OP_NotFound, base+idx, brk);
        haveKey = 0;
      }
      pLevel->op = OP_Noop;
    }else if( pIdx!=0 && pLevel->score%4==0 ){
      /* Case 2:  All index constraints are equality operators.

#    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 magic ROWID column that is
# found on all tables.
#
# $Id: rowid.test,v 1.7 2002/01/04 03:09:30 drh Exp $

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

# Basic ROWID functionality tests.
#
do_test rowid-1.1 {

  }
} {4}

do_test rowid-5.1 {
  execsql {DELETE FROM t1 WHERE _rowid_ IN (SELECT oid FROM t1 WHERE x>8)}
  execsql {SELECT max(x) FROM t1}
} {8}

# Make sure a "WHERE rowid=X" clause works when there is no ROWID of X.
#
do_test rowid-6.1 {
  execsql {
    SELECT x FROM t1
  }
} {1 2 3 4 5 6 7 8}
do_test rowid-6.2 {
  for {set ::norow 1} {[execsql {SELECT x FROM t1 WHERE rowid=10}]!=""} \
    {incr ::norow} {}
  execsql [subst {
    DELETE FROM t1 WHERE rowid=$::norow
  }]
} {}
do_test rowid-6.3 {
  execsql {
    SELECT x FROM t1
  }
} {1 2 3 4 5 6 7 8}


finish_test

}


proc chng {date desc} {
  puts "<DT><B>$date</B></DT>"
  puts "<DD><P><UL>$desc</UL></P></DD>"
}

chng {2002 Jan 3 (2.2.1)} {
<li>Bug fix: An attempt to delete a single row of a table with a WHERE
    clause of "ROWID=x" when no such rowid exists was causing an error.</li>
}

chng {2001 Dec 22 (2.2.0)} {
<li>Columns of type INTEGER PRIMARY KEY are actually used as the primary
    key in underlying B-Tree representation of the table.</li>
<li>Several obscure, unrelated bugs were found and fixed while 
    implemented the integer primary key change of the previous bullet.</li>
<li>Added the ability to specify "*" as part of a larger column list in