SQLite

  */
  zNew = sqlite3NameFromToken(db, pNew);
  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, type, name, %Q, %Q, %d, %Q, %d) "
      "WHERE name NOT LIKE 'sqlite_%%' AND (type != 'index' OR tbl_name = %Q)"
      " AND sql NOT LIKE 'create virtual%%'",
      zDb, MASTER_NAME, 
      zDb, pTab->zName, iCol, zNew, bQuote,
      pTab->zName
  );

/*
** If there is a RenameToken object associated with parse tree element
** pFrom, then remap that object over to pTo due to a transformation
** in the parse tree.
*/
void sqlite3MoveRenameToken(Parse *pParse, void *pTo, void *pFrom){
  RenameToken *p;
  for(p=pParse->pRename; ALWAYS(p); p=p->pNext){
    if( p->p==pFrom ){
      p->p = pTo;
      break;
    }
  }
  assert( p );
}

/*
** An error occured while parsing or otherwise processing a database
** object (either pParse->pNewTable, pNewIndex or pNewTrigger) as part of an
** ALTER TABLE RENAME COLUMN program. The error message emitted by the
** sub-routine is currently stored in pParse->zErrMsg. This function
** adds context to the error message and then stores it in pCtx.
*/
static void renameColumnParseError(
  sqlite3_context *pCtx, 
  sqlite3_value *pType,
  sqlite3_value *pObject,
  Parse *pParse
){
  const char *zT = sqlite3_value_text(pType);
  const char *zN = sqlite3_value_text(pObject);
  char *zErr;











  zErr = sqlite3_mprintf("error processing %s %s: %s", zT, zN, pParse->zErrMsg);
  sqlite3_result_error(pCtx, zErr, -1);
  sqlite3_free(zErr);
}

/*
** SQL function:
**
**     sqlite_rename_column(zSql, iCol, bQuote, zNew, zTable, zOld)
**
**   0. zSql:     SQL statement to rewrite
**   1. type:     Type of object ("table", "view" etc.)
**   2. object:   Name of object
**   3. Database: Database name (e.g. "main")
**   4. Table:    Table name
**   5. iCol:     Index of column to rename
**   6. zNew:     New column name
**   7. bQuote:   True if the new column name should be quoted
**
** Do a column rename operation on the CREATE statement given in zSql.
** The iCol-th column (left-most is 0) of table zTable is renamed from zCol
** into zNew.  The name should be quoted if bQuote is true.
**
** This function is used internally by the ALTER TABLE RENAME COLUMN command.
** Though accessible to application code, it is not intended for use by

  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]);
  const char *zDb = (const char*)sqlite3_value_text(argv[3]);
  const char *zTable = (const char*)sqlite3_value_text(argv[4]);
  int iCol = sqlite3_value_int(argv[5]);
  const char *zNew = (const char*)sqlite3_value_text(argv[6]);
  int nNew = sqlite3_value_bytes(argv[6]);
  int bQuote = sqlite3_value_int(argv[7]);
  const char *zOld;

  int rc;
  char *zErr = 0;
  Parse sParse;
  Walker sWalker;
  Index *pIdx;
  char *zOut = 0;

  char *zQuot = 0;                /* Quoted version of zNew */
  int nQuot = 0;                  /* Length of zQuot in bytes */
  int i;
  Table *pTab;

  UNUSED_PARAMETER(NotUsed);
  if( zSql==0 ) return;
  if( zTable==0 ) return;
  if( zNew==0 ) return;
  if( iCol<0 ) return;
  pTab = sqlite3FindTable(db, zTable, zDb);
  if( pTab==0 || iCol>=pTab->nCol ) return;
  zOld = pTab->aCol[iCol].zName;
  memset(&sCtx, 0, sizeof(sCtx));
  sCtx.iCol = ((iCol==pTab->iPKey) ? -1 : iCol);

      rc = sqlite3ResolveExprNames(&sNC, sParse.pNewTrigger->pWhen);
    }

    for(pStep=sParse.pNewTrigger->step_list; 
        rc==SQLITE_OK && pStep; 
        pStep=pStep->pNext
    ){
      if( pStep->pSelect ){
        sqlite3SelectPrep(&sParse, pStep->pSelect, &sNC);
        if( sParse.nErr ) rc = sParse.rc;
      }
      if( rc==SQLITE_OK && pStep->zTarget ){ 
        Table *pTarget = sqlite3FindTable(db, pStep->zTarget, zDb);
        if( pTarget==0 ){
          rc = SQLITE_ERROR;
        }else{
          SrcList sSrc;
          memset(&sSrc, 0, sizeof(sSrc));
          sSrc.nSrc = 1;
          sSrc.a[0].zName = pStep->zTarget;
          sSrc.a[0].pTab = pTarget;
          sNC.pSrcList = &sSrc;
          if( pStep->pWhere ){
            rc = sqlite3ResolveExprNames(&sNC, pStep->pWhere);
          }
          if( rc==SQLITE_OK ){
            rc = sqlite3ResolveExprListNames(&sNC, pStep->pExprList);
          }
          assert( !pStep->pUpsert || (!pStep->pWhere && !pStep->pExprList) );
          if( pStep->pUpsert ){
            Upsert *pUpsert = pStep->pUpsert;
            assert( rc==SQLITE_OK );
            rc = sqlite3ResolveExprListNames(&sNC, pUpsert->pUpsertTarget);

            if( rc==SQLITE_OK && pUpsert->pUpsertSet){
              ExprList *pUpsertSet = pUpsert->pUpsertSet;
              rc = sqlite3ResolveExprListNames(&sNC, pUpsertSet);
              if( rc==SQLITE_OK && pTarget==pTab ){
                for(i=0; i<pUpsertSet->nExpr; i++){
                  char *zName = pUpsertSet->a[i].zName;
                  if( 0==sqlite3_stricmp(zName, zOld) ){

  }else{
    rc = SQLITE_NOMEM;
  }

renameColumnFunc_done:
  if( rc!=SQLITE_OK ){
    if( sParse.zErrMsg ){
      renameColumnParseError(context, argv[1], argv[2], &sParse);
    }else{
      sqlite3_result_error_code(context, rc);
    }
  }

  if( sParse.pVdbe ){
    sqlite3VdbeFinalize(sParse.pVdbe);

/*
** Register built-in functions used to help implement ALTER TABLE
*/
void sqlite3AlterFunctions(void){
  static FuncDef aAlterTableFuncs[] = {
    FUNCTION(sqlite_rename_table,   2, 0, 0, renameTableFunc),
    FUNCTION(sqlite_rename_column,   8, 0, 0, renameColumnFunc),
#ifndef SQLITE_OMIT_TRIGGER
    FUNCTION(sqlite_rename_trigger, 2, 0, 0, renameTriggerFunc),
#endif
#ifndef SQLITE_OMIT_FOREIGN_KEY
    FUNCTION(sqlite_rename_parent,  3, 0, 0, renameParentFunc),
#endif
  };
  sqlite3InsertBuiltinFuncs(aAlterTableFuncs, ArraySize(aAlterTableFuncs));
}
#endif  /* SQLITE_ALTER_TABLE */

  4 _x_ _xxx_ {
    { CREATE TABLE t1(a, b, _x_ INTEGER, PRIMARY KEY(_x_), CHECK(_x_>0)) }
    { CREATE TRIGGER ttt AFTER UPDATE  ON t1 BEGIN
        INSERT INTO t1 VALUES(new.a, new.b, new._x_)
          ON CONFLICT (_x_) WHERE _x_>10 DO UPDATE SET _x_ = _x_+1;
      END }
  }

  4 _x_ _xxx_ {
    { CREATE TABLE t1(a, b, _x_ INTEGER, PRIMARY KEY(_x_), CHECK(_x_>0)) }
    { CREATE TRIGGER ttt AFTER UPDATE  ON t1 BEGIN
        INSERT INTO t1 VALUES(new.a, new.b, new._x_)
          ON CONFLICT (_x_) WHERE _x_>10 DO NOTHING;
      END }
  }
} {
  do_rename_column_test 9.$tn $old $new $lSchema
}

#-------------------------------------------------------------------------
# Test that views can be edited even if there are missing collation 
# sequences or user defined functions.

#-------------------------------------------------------------------------
# Test some error conditions:
#
#   1. Renaming a column of a system table,
#   2. Renaming a column of a VIEW,
#   3. Renaming a column of a virtual table.
#   4. Renaming a column that does not exist.
#   5. Renaming a column of a table that does not exist.
#
reset_db
do_execsql_test 12.1.1 {
  CREATE TABLE t1(a, b);
  CREATE INDEX t1a ON t1(a);
  INSERT INTO t1 VALUES(1, 1), (2, 2), (3, 4);
  ANALYZE;

  ALTER TABLE v2 RENAME c TO y;
} {1 {columns of view v2 may not be renamed}}

ifcapable fts5 {
  do_execsql_test 12.3.1 {
    CREATE VIRTUAL TABLE ft USING fts5(a, b, c);
  }
  do_catchsql_test 12.3.2 {
    ALTER TABLE ft RENAME a TO z;
  } {1 {columns of virtual table ft may not be renamed}}
}

do_execsql_test 12.4.1 {
  CREATE TABLE t2(x, y, z);
}
do_catchsql_test 12.4.2 {
  ALTER TABLE t2 RENAME COLUMN a TO b;
} {1 {no such column: "a"}}

do_catchsql_test 12.5.1 {
  ALTER TABLE t3 RENAME COLUMN a TO b;
} {1 {no such table: t3}}

#-------------------------------------------------------------------------
# Test the effect of some parse/resolve errors.
#
reset_db
do_execsql_test 13.1.1 {
  CREATE TABLE x1(i INTEGER, t TEXT UNIQUE);
  CREATE TRIGGER tr1 AFTER INSERT ON x1 BEGIN
    SELECT * FROM nosuchtable;
  END;
}

do_catchsql_test 13.1.2 {
  ALTER TABLE x1 RENAME COLUMN t TO ttt;
} {1 {error processing trigger tr1: no such table: main.nosuchtable}}

do_execsql_test 13.1.3 {
  DROP TRIGGER tr1;
  CREATE INDEX x1i ON x1(i);
  SELECT sql FROM sqlite_master WHERE name='x1i';
} {{CREATE INDEX x1i ON x1(i)}}

do_execsql_test 13.1.4 {
  PRAGMA writable_schema = 1;
  UPDATE sqlite_master SET sql = 'CREATE INDEX x1i ON x1(j)' WHERE name='x1i';
} {}

do_catchsql_test 13.1.5 {
  ALTER TABLE x1 RENAME COLUMN t TO ttt;
} {1 {error processing index x1i: no such column: j}}

do_execsql_test 13.1.6 {
  UPDATE sqlite_master SET sql = '' WHERE name='x1i';
} {}

do_catchsql_test 13.1.7 {
  ALTER TABLE x1 RENAME COLUMN t TO ttt;
} {1 {database disk image is malformed}}

do_execsql_test 13.1.8 {
  DELETE FROM sqlite_master WHERE name = 'x1i';
}

do_execsql_test 13.2.0 {
  CREATE TABLE data(x UNIQUE, y, z);
}
foreach {tn trigger error} {
  1 {
    CREATE TRIGGER tr1 AFTER INSERT ON x1 BEGIN
      UPDATE data SET x=x+1 WHERE zzz=new.i;
    END;
  } {no such column: zzz}

  2 {
    CREATE TRIGGER tr1 AFTER INSERT ON x1 BEGIN
      INSERT INTO data(x, y) VALUES(new.i, new.t, 1) 
        ON CONFLICT (x) DO UPDATE SET z=zz+1;
    END;
  } {no such column: zz}

  3 {
    CREATE TRIGGER tr1 AFTER INSERT ON x1 BEGIN
      INSERT INTO x1(i, t) VALUES(new.i+1, new.t||'1') 
        ON CONFLICT (tttttt) DO UPDATE SET t=i+1;
    END;
  } {no such column: tttttt}


} {
  do_execsql_test 13.2.$tn.1 "
    DROP TRIGGER IF EXISTS tr1;
    $trigger
  "

  do_catchsql_test 13.2.$tn.2 {
    ALTER TABLE x1 RENAME COLUMN t TO ttt;
  } "1 {error processing trigger tr1: $error}"
}

#-------------------------------------------------------------------------
# Passing invalid parameters directly to sqlite_rename_column().
#
do_execsql_test 14.1 {
  CREATE TABLE ddd(sql, type, object, db, tbl, icol, znew, bquote);
  INSERT INTO ddd VALUES(
      'CREATE TABLE x1(i INTEGER, t TEXT)',
      'table', 'x1', 'main', 'x1', -1, 'zzz', 0
  ), (
      'CREATE TABLE x1(i INTEGER, t TEXT)',
      'table', 'x1', 'main', 'x1', 2, 'zzz', 0
  ), (
      'CREATE TABLE x1(i INTEGER, t TEXT)',
      'table', 'x1', 'main', 'notable', 0, 'zzz', 0
  );
} {}

do_execsql_test 14.2 {
  SELECT 
  sqlite_rename_column(sql, type, object, db, tbl, icol, znew, bquote)
  FROM ddd;
} {{} {} {}}


finish_test

# 2018 August 20
#
# 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.
#
#*************************************************************************
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
source $testdir/malloc_common.tcl
set testprefix altermalloc2

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

do_execsql_test 1.0 {
  CREATE TABLE t1(abcd, efgh);
}
faultsim_save_and_close

do_faultsim_test 1 -prep {
  faultsim_restore_and_reopen
} -body {
  execsql {
    ALTER TABLE t1 RENAME abcd TO dcba
  }
} -test {
  faultsim_test_result {0 {}}
}

catch {db close}
forcedelete test.db
sqlite3 db test.db
do_execsql_test 2.0 {
  PRAGMA encoding = 'utf-16';
  CREATE TABLE t1(abcd, efgh);
}
faultsim_save_and_close

do_faultsim_test 2 -prep {
  faultsim_restore_and_reopen
} -body {
  execsql {
    ALTER TABLE t1 RENAME abcd TO dcba
  }
} -test {
  faultsim_test_result {0 {}}
}


reset_db
do_execsql_test 3.0 {
  CREATE TABLE t1(abcd, efgh);
  CREATE VIEW v1 AS SELECT * FROM t1 WHERE abcd>efgh;
}
faultsim_save_and_close

do_faultsim_test 3 -prep {
  faultsim_restore_and_reopen
} -body {
  execsql {
    ALTER TABLE t1 RENAME abcd TO dcba
  }
} -test {
  faultsim_test_result {0 {}}
}
finish_test