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 used to generate VDBE code
** that implements the ALTER TABLE command.
**
** $Id: alter.c,v 1.53 2009/02/13 03:43:32 drh Exp $
*/
#include "sqliteInt.h"

/*
** The code in this file only exists if we are not omitting the
** ALTER TABLE logic from the build.
*/

  if( pParse->nErr || db->mallocFailed ) return;
  pNew = pParse->pNewTable;
  assert( pNew );

  assert( sqlite3BtreeHoldsAllMutexes(db) );
  iDb = sqlite3SchemaToIndex(db, pNew->pSchema);
  zDb = db->aDb[iDb].zName;
  zTab = &pNew->zName[16];  /* Skip the "sqlite_altertab_" prefix on the name */
  pCol = &pNew->aCol[pNew->nCol-1];
  pDflt = pCol->pDflt;
  pTab = sqlite3FindTable(db, zTab, zDb);
  assert( pTab );

#ifndef SQLITE_OMIT_AUTHORIZATION
  /* Invoke the authorization callback. */

    goto exit_begin_add_column;
  }

  assert( pTab->addColOffset>0 );
  iDb = sqlite3SchemaToIndex(db, pTab->pSchema);

  /* Put a copy of the Table struct in Parse.pNewTable for the
  ** sqlite3AddColumn() function and friends to modify.  But modify
  ** the name by adding an "sqlite_altertab_" prefix.  By adding this
  ** prefix, we insure that the name will not collide with an existing
  ** table because user table are not allowed to have the "sqlite_"
  ** prefix on their name.
  */
  pNew = (Table*)sqlite3DbMallocZero(db, sizeof(Table));
  if( !pNew ) goto exit_begin_add_column;
  pParse->pNewTable = pNew;
  pNew->nRef = 1;
  pNew->db = db;
  pNew->nCol = pTab->nCol;
  assert( pNew->nCol>0 );
  nAlloc = (((pNew->nCol-1)/8)*8)+8;
  assert( nAlloc>=pNew->nCol && nAlloc%8==0 && nAlloc-pNew->nCol<8 );
  pNew->aCol = (Column*)sqlite3DbMallocZero(db, sizeof(Column)*nAlloc);
  pNew->zName = sqlite3MPrintf(db, "sqlite_altertab_%s", pTab->zName);
  if( !pNew->aCol || !pNew->zName ){
    db->mallocFailed = 1;
    goto exit_begin_add_column;
  }
  memcpy(pNew->aCol, pTab->aCol, sizeof(Column)*pNew->nCol);
  for(i=0; i<pNew->nCol; i++){
    Column *pCol = &pNew->aCol[i];

**     CREATE INDEX
**     DROP INDEX
**     creating ID lists
**     BEGIN TRANSACTION
**     COMMIT
**     ROLLBACK
**
** $Id: build.c,v 1.518 2009/02/13 03:43:32 drh Exp $
*/
#include "sqliteInt.h"

/*
** This routine is called when a new SQL statement is beginning to
** be parsed.  Initialize the pParse structure as needed.
*/

** Remove the given index from the index hash table, and free
** its memory structures.
**
** The index is removed from the database hash tables but
** it is not unlinked from the Table that it indexes.
** Unlinking from the Table must be done by the calling function.
*/
static void sqlite3DeleteIndex(Index *p){
  Index *pOld;
  const char *zName = p->zName;

  pOld = sqlite3HashInsert(&p->pSchema->idxHash, zName,
                           sqlite3Strlen30(zName)+1, 0);
  assert( pOld==0 || pOld==p );
  freeIndex(p);

  assert( pTable->nRef==0 );

  /* Delete all indices associated with this table
  */
  for(pIndex = pTable->pIndex; pIndex; pIndex=pNext){
    pNext = pIndex->pNext;
    assert( pIndex->pSchema==pTable->pSchema );
    sqlite3DeleteIndex(pIndex);
  }

#ifndef SQLITE_OMIT_FOREIGN_KEY
  /* Delete all foreign keys associated with this table.  The keys
  ** should have already been unlinked from the pSchema->aFKey hash table 
  */
  for(pFKey=pTable->pFKey; pFKey; pFKey=pNextFKey){

    pTab = pParse->pNewTable;
    if( !pTab ) goto exit_create_index;
    iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
  }
  pDb = &db->aDb[iDb];

  if( pTab==0 || pParse->nErr ) goto exit_create_index;
  if( sqlite3StrNICmp(pTab->zName, "sqlite_", 7)==0 
       && memcmp(&pTab->zName[7],"altertab_",9)!=0 ){
    sqlite3ErrorMsg(pParse, "table %s may not be indexed", pTab->zName);
    goto exit_create_index;
  }
#ifndef SQLITE_OMIT_VIEW
  if( pTab->pSelect ){
    sqlite3ErrorMsg(pParse, "views may not be indexed");
    goto exit_create_index;

# 2004 November 10
#
# 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 script is testing the ALTER TABLE statement.
#
# $Id: alter.test,v 1.31 2009/02/13 03:43:32 drh Exp $
#

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

# If SQLITE_OMIT_ALTERTABLE is defined, omit this file.
ifcapable !altertable {

} {t3102a_rename t3102b t3102c}
do_test alter-13.3 {
  execsql {
    ALTER TABLE t3102b RENAME TO t3102b_rename;
    SELECT name FROM sqlite_master WHERE name LIKE 't3102%' ORDER BY 1;
  }
} {t3102a_rename t3102b_rename t3102c}

# Ticket #3651
do_test alter-14.1 {
  catchsql {
    CREATE TABLE t3651(a UNIQUE);
    ALTER TABLE t3651 ADD COLUMN b UNIQUE;
  }
} {1 {Cannot add a UNIQUE column}}
do_test alter-14.2 {
  catchsql {
    ALTER TABLE t3651 ADD COLUMN b PRIMARY KEY;
  }
} {1 {Cannot add a PRIMARY KEY column}}


finish_test