SQLite

  if( !zNew ) goto exit_rename_column;
  assert( pNew->n>0 );
  bQuote = sqlite3Isquote(pNew->z[0]);
  sqlite3NestedParse(pParse, 
      "UPDATE \"%w\".%s SET "
      "sql = sqlite_rename_column(sql, %d, %d, %Q, %Q, %Q) "
      "WHERE name NOT LIKE 'sqlite_%%' AND ("
      "   type = 'table' OR (type IN ('index', 'trigger') AND tbl_name = %Q)"
      ")",
      zDb, MASTER_NAME, iCol, bQuote, zNew, pTab->zName, zOld, pTab->zName
  );

  /* Drop and reload the database schema. */
  if( pParse->pVdbe ){
    sqlite3ChangeCookie(pParse, iSchema);

  RenameToken *pNext;    /* Next is a list of all RenameToken objects */
};

/*
** The context of an ALTER TABLE RENAME COLUMN operation that gets passed
** down into the Walker.
*/
typedef struct RenameCtx RenameCtx;
struct RenameCtx {
  RenameToken *pList;             /* List of tokens to overwrite */
  int nList;                      /* Number of tokens in pList */
  int iCol;                       /* Index of column being renamed */
  const char *zOld;               /* Old column name */
};

/*
** Add a new RenameToken object mapping parse tree element pPtr into
** token *pToken to the Parse object currently under construction.
*/
void sqlite3RenameToken(Parse *pParse, void *pPtr, Token *pToken){

  RenameToken *p;
  for(p=pToken; p; p=pNext){
    pNext = p->pNext;
    sqlite3DbFree(db, p);
  }
}

static void renameTokenFind(Parse *pParse, RenameCtx *pCtx, void *pPtr){
  RenameToken **pp;
  for(pp=&pParse->pRename; (*pp); pp=&(*pp)->pNext){
    if( (*pp)->p==pPtr ){
      RenameToken *pToken = *pp;
      *pp = pToken->pNext;
      pToken->pNext = pCtx->pList;
      pCtx->pList = pToken;
      pCtx->nList++;
      break;
    }
  }

}

static int renameColumnExprCb(Walker *pWalker, Expr *pExpr){
  RenameCtx *p = pWalker->u.pRename;
  if( p->zOld && pExpr->op==TK_DOT ){
    Expr *pLeft = pExpr->pLeft;
    Expr *pRight = pExpr->pRight;
    assert( pLeft->op==TK_ID && pRight->op==TK_ID );
    if( 0==sqlite3_stricmp(pLeft->u.zToken, "old")
     || 0==sqlite3_stricmp(pLeft->u.zToken, "new")
    ){
      if( 0==sqlite3_stricmp(pRight->u.zToken, p->zOld) ){
        renameTokenFind(pWalker->pParse, p, (void*)pRight);




      }
    }
  }else if( pExpr->op==TK_COLUMN && pExpr->iColumn==p->iCol ){
    renameTokenFind(pWalker->pParse, p, (void*)pExpr);
  }
  return WRC_Continue;
}

static RenameToken *renameColumnTokenNext(RenameCtx *pCtx){
  RenameToken *pBest = pCtx->pList;
  RenameToken *pToken;
  RenameToken **pp;

  for(pToken=pBest->pNext; pToken; pToken=pToken->pNext){
    if( pToken->t.z>pBest->t.z ) pBest = pToken;
  }

*/
static void renameColumnFunc(
  sqlite3_context *context,
  int NotUsed,
  sqlite3_value **argv
){
  sqlite3 *db = sqlite3_context_db_handle(context);
  RenameCtx sCtx;
  const char *zSql = (const char*)sqlite3_value_text(argv[0]);
  int nSql = sqlite3_value_bytes(argv[0]);
  int bQuote = sqlite3_value_int(argv[2]);
  const char *zNew = (const char*)sqlite3_value_text(argv[3]);
  int nNew = sqlite3_value_bytes(argv[3]);
  const char *zTable = (const char*)sqlite3_value_text(argv[4]);
  const char *zOld = (const char*)sqlite3_value_text(argv[5]);

  memset(&sParse, 0, sizeof(sParse));
  sParse.eParseMode = PARSE_MODE_RENAME_COLUMN;
  sParse.db = db;
  sParse.nQueryLoop = 1;
  rc = sqlite3RunParser(&sParse, zSql, &zErr);
  assert( sParse.pNewTable==0 || sParse.pNewIndex==0 );
  if( db->mallocFailed ) rc = SQLITE_NOMEM;
  if( rc==SQLITE_OK 
   && sParse.pNewTable==0 && sParse.pNewIndex==0 && sParse.pNewTrigger==0 
  ){
    rc = SQLITE_CORRUPT_BKPT;
  }

  if( rc==SQLITE_OK ){
    zQuot = sqlite3_mprintf("\"%w\"", zNew);
    if( zQuot==0 ){
      rc = SQLITE_NOMEM;

  sWalker.xExprCallback = renameColumnExprCb;
  sWalker.u.pRename = &sCtx;

  if( sParse.pNewTable ){
    int bFKOnly = sqlite3_stricmp(zTable, sParse.pNewTable->zName);
    FKey *pFKey;
    if( bFKOnly==0 ){
      renameTokenFind(
          &sParse, &sCtx, (void*)sParse.pNewTable->aCol[sCtx.iCol].zName
      );

      assert( sCtx.iCol>=0 );
      if( sParse.pNewTable->iPKey==sCtx.iCol ){
        sCtx.iCol = -1;
      }
      sqlite3WalkExprList(&sWalker, sParse.pNewTable->pCheck);
      for(pIdx=sParse.pNewTable->pIndex; pIdx; pIdx=pIdx->pNext){
        sqlite3WalkExprList(&sWalker, pIdx->aColExpr);
      }
    }

    for(pFKey=sParse.pNewTable->pFKey; pFKey; pFKey=pFKey->pNextFrom){
      for(i=0; i<pFKey->nCol; i++){

        if( bFKOnly==0 && pFKey->aCol[i].iFrom==sCtx.iCol ){
          renameTokenFind(&sParse, &sCtx, (void*)&pFKey->aCol[i]);





        }
        if( 0==sqlite3_stricmp(pFKey->zTo, zTable)
         && 0==sqlite3_stricmp(pFKey->aCol[i].zCol, zOld)
        ){
          renameTokenFind(&sParse, &sCtx, (void*)pFKey->aCol[i].zCol);



        }
      }
    }
  }else if( sParse.pNewIndex ){
    sqlite3WalkExprList(&sWalker, sParse.pNewIndex->aColExpr);
    sqlite3WalkExpr(&sWalker, sParse.pNewIndex->pPartIdxWhere);
  }else{
    sCtx.zOld = zOld;
    sqlite3WalkExpr(&sWalker, sParse.pNewTrigger->pWhen);
    if( sParse.pNewTrigger->pColumns ){
      for(i=0; i<sParse.pNewTrigger->pColumns->nId; i++){
        char *zName = sParse.pNewTrigger->pColumns->a[i].zName;
        if( 0==sqlite3_stricmp(zName, zOld) ){
          renameTokenFind(&sParse, &sCtx, (void*)zName);
        }
      }
    }
  }

  assert( nQuot>=nNew );
  zOut = sqlite3DbMallocZero(db, nSql + sCtx.nList*nQuot + 1);
  if( zOut ){
    int nOut = nSql;
    memcpy(zOut, zSql, nSql);

renameColumnFunc_done:
  if( sParse.pVdbe ){
    sqlite3VdbeFinalize(sParse.pVdbe);
  }
  sqlite3DeleteTable(db, sParse.pNewTable);
  if( sParse.pNewIndex ) sqlite3FreeIndex(db, sParse.pNewIndex);
  sqlite3DeleteTrigger(db, sParse.pNewTrigger);
  renameTokenFree(db, sParse.pRename);
  renameTokenFree(db, sCtx.pList);
  sqlite3ParserReset(&sParse);
  sqlite3_free(zQuot);
}

/*

/*
** Append a new element to the given IdList.  Create a new IdList if
** need be.
**
** A new IdList is returned, or NULL if malloc() fails.
*/
IdList *sqlite3IdListAppend(Parse *pParse, IdList *pList, Token *pToken){
  sqlite3 *db = pParse->db;
  int i;
  if( pList==0 ){
    pList = sqlite3DbMallocZero(db, sizeof(IdList) );
    if( pList==0 ) return 0;
  }
  pList->a = sqlite3ArrayAllocate(
      db,
      pList->a,
      sizeof(pList->a[0]),
      &pList->nId,
      &i
  );
  if( i<0 ){
    sqlite3IdListDelete(db, pList);
    return 0;
  }
  pList->a[i].zName = sqlite3NameFromToken(db, pToken);
  if( IN_RENAME_COLUMN && pList->a[i].zName ){
    sqlite3RenameToken(pParse, (void*)pList->a[i].zName, pToken);
  }
  return pList;
}

/*
** Delete an IdList.
*/
void sqlite3IdListDelete(sqlite3 *db, IdList *pList){

%destructor idlist_opt {sqlite3IdListDelete(pParse->db, $$);}
%type idlist {IdList*}
%destructor idlist {sqlite3IdListDelete(pParse->db, $$);}

idlist_opt(A) ::= .                       {A = 0;}
idlist_opt(A) ::= LP idlist(X) RP.    {A = X;}
idlist(A) ::= idlist(A) COMMA nm(Y).
    {A = sqlite3IdListAppend(pParse,A,&Y);}
idlist(A) ::= nm(Y).
    {A = sqlite3IdListAppend(pParse,0,&Y); /*A-overwrites-Y*/}

/////////////////////////// Expression Processing /////////////////////////////
//

%type expr {Expr*}
%destructor expr {sqlite3ExprDelete(pParse->db, $$);}
%type term {Expr*}

  void sqlite3AutoincrementEnd(Parse *pParse);
#else
# define sqlite3AutoincrementBegin(X)
# define sqlite3AutoincrementEnd(X)
#endif
void sqlite3Insert(Parse*, SrcList*, Select*, IdList*, int, Upsert*);
void *sqlite3ArrayAllocate(sqlite3*,void*,int,int*,int*);
IdList *sqlite3IdListAppend(Parse*, IdList*, Token*);
int sqlite3IdListIndex(IdList*,const char*);
SrcList *sqlite3SrcListEnlarge(sqlite3*, SrcList*, int, int);
SrcList *sqlite3SrcListAppend(sqlite3*, SrcList*, Token*, Token*);
SrcList *sqlite3SrcListAppendFromTerm(Parse*, SrcList*, Token*, Token*,
                                      Token*, Select*, Expr*, IdList*);
void sqlite3SrcListIndexedBy(Parse *, SrcList *, Token *);
void sqlite3SrcListFuncArgs(Parse*, SrcList*, ExprList*);

  if( !IN_SPECIAL_PARSE ){
    /* If the pParse->declareVtab flag is set, do not delete any table 
    ** structure built up in pParse->pNewTable. The calling code (see vtab.c)
    ** will take responsibility for freeing the Table structure.
    */
    sqlite3DeleteTable(db, pParse->pNewTable);
  }
  if( !IN_RENAME_COLUMN ){
    sqlite3DeleteTrigger(db, pParse->pNewTrigger);
  }

  if( pParse->pWithToFree ) sqlite3WithDelete(db, pParse->pWithToFree);

  sqlite3DbFree(db, pParse->pVList);
  while( pParse->pAinc ){
    AutoincInfo *p = pParse->pAinc;
    pParse->pAinc = p->pNext;
    sqlite3DbFreeNN(db, p);
  }
  while( pParse->pZombieTab ){

  /* Check that the trigger name is not reserved and that no trigger of the
  ** specified name exists */
  zName = sqlite3NameFromToken(db, pName);
  if( !zName || SQLITE_OK!=sqlite3CheckObjectName(pParse, zName) ){
    goto trigger_cleanup;
  }
  assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
  if( !IN_RENAME_COLUMN ){
    if( sqlite3HashFind(&(db->aDb[iDb].pSchema->trigHash),zName) ){
      if( !noErr ){
        sqlite3ErrorMsg(pParse, "trigger %T already exists", pName);
      }else{
        assert( !db->init.busy );
        sqlite3CodeVerifySchema(pParse, iDb);
      }
      goto trigger_cleanup;
    }
  }

  /* Do not create a trigger on a system table */
  if( sqlite3StrNICmp(pTab->zName, "sqlite_", 7)==0 ){
    sqlite3ErrorMsg(pParse, "cannot create trigger on system table");
    goto trigger_cleanup;
  }

  if( !pTab->pSelect && tr_tm==TK_INSTEAD ){
    sqlite3ErrorMsg(pParse, "cannot create INSTEAD OF"
        " trigger on table: %S", pTableName, 0);
    goto trigger_cleanup;
  }

#ifndef SQLITE_OMIT_AUTHORIZATION

  if( !IN_RENAME_COLUMN ){
    int iTabDb = sqlite3SchemaToIndex(db, pTab->pSchema);
    int code = SQLITE_CREATE_TRIGGER;
    const char *zDb = db->aDb[iTabDb].zDbSName;
    const char *zDbTrig = isTemp ? db->aDb[1].zDbSName : zDb;
    if( iTabDb==1 || isTemp ) code = SQLITE_CREATE_TEMP_TRIGGER;
    if( sqlite3AuthCheck(pParse, code, zName, pTab->zName, zDbTrig) ){
      goto trigger_cleanup;

  pTrigger->zName = zName;
  zName = 0;
  pTrigger->table = sqlite3DbStrDup(db, pTableName->a[0].zName);
  pTrigger->pSchema = db->aDb[iDb].pSchema;
  pTrigger->pTabSchema = pTab->pSchema;
  pTrigger->op = (u8)op;
  pTrigger->tr_tm = tr_tm==TK_BEFORE ? TRIGGER_BEFORE : TRIGGER_AFTER;
  if( IN_RENAME_COLUMN ){
    pTrigger->pWhen = pWhen;
    pWhen = 0;
  }else{
    pTrigger->pWhen = sqlite3ExprDup(db, pWhen, EXPRDUP_REDUCE);
  }
  pTrigger->pColumns = pColumns;
  pColumns = 0;
  assert( pParse->pNewTrigger==0 );
  pParse->pNewTrigger = pTrigger;

trigger_cleanup:
  sqlite3DbFree(db, zName);
  sqlite3SrcListDelete(db, pTableName);
  sqlite3IdListDelete(db, pColumns);

  sqlite3TokenInit(&nameToken, pTrig->zName);
  sqlite3FixInit(&sFix, pParse, iDb, "trigger", &nameToken);
  if( sqlite3FixTriggerStep(&sFix, pTrig->step_list) 
   || sqlite3FixExpr(&sFix, pTrig->pWhen) 
  ){
    goto triggerfinish_cleanup;
  }

#ifndef SQLITE_OMIT_ALTERTABLE
  if( IN_RENAME_COLUMN ){
    assert( !db->init.busy );
    pParse->pNewTrigger = pTrig;
    pTrig = 0;
  }else
#endif

  /* if we are not initializing,
  ** build the sqlite_master entry
  */
  if( !db->init.busy ){
    Vdbe *v;
    char *z;

      pLink->pNext = pTab->pTrigger;
      pTab->pTrigger = pLink;
    }
  }

triggerfinish_cleanup:
  sqlite3DeleteTrigger(db, pTrig);
  assert( IN_RENAME_COLUMN || !pParse->pNewTrigger );
  sqlite3DeleteTriggerStep(db, pStepList);
}

/*
** Duplicate a range of text from an SQL statement, then convert all
** whitespace characters into ordinary space characters.
*/

db close
sqlite3 db test.db

do_execsql_test 3.2 {
  SELECT * FROM t4;
} {3 2 1}

do_execsql_test 3.3 { INSERT INTO t4 VALUES(6, 5, 4); } {}

#-------------------------------------------------------------------------
#
do_execsql_test 4.0 {
  CREATE TABLE c1(a, b, FOREIGN KEY (a, b) REFERENCES p1(c, d));
  CREATE TABLE p1(c, d, PRIMARY KEY(c, d));
  PRAGMA foreign_keys = 1;

do_catchsql_test 6.2 {
  ALTER TABLE "blob" RENAME COLUMN "a1" TO [where];
} {0 {}}

do_execsql_test 6.3 {
  SELECT "where" FROM blob;
} {}

#-------------------------------------------------------------------------
#
reset_db
do_execsql_test 7.0 {
  CREATE TABLE c(x);
  INSERT INTO c VALUES(0);
  CREATE TABLE t6("col a", "col b", "col c");
  CREATE TRIGGER zzz AFTER UPDATE OF "col a", "col c" ON t6 BEGIN
    UPDATE c SET x=x+1;
  END;
}

do_execsql_test 7.1 {
  INSERT INTO t6 VALUES(0, 0, 0);
  UPDATE t6 SET "col c" = 1;
  SELECT * FROM c;
} {1}

do_execsql_test 7.2 {
  ALTER TABLE t6 RENAME "col c" TO "col 3";
}

do_execsql_test 7.3 {
  UPDATE t6 SET "col 3" = 0;
  SELECT * FROM c;
} {2}

finish_test