down method

@override Future<void> down()

Migration down - rollback schema

Implementation

@override
Future<void> down() async {
  if (downSqlStatements != null && downSqlStatements!.isNotEmpty) {
    for (final sql in downSqlStatements!) {
      await connection.execute(sql);
    }
  } else if (downSql != null && downSql!.isNotEmpty) {
    await connection.execute(downSql!);
  }
}