NoSuchMethodError: The method 'rawinsert' was called on null

Question

Getting this error when I try to login into the app I created. Also this error only comes for Iphone or Ipad. It works fine for ios simulators, android emulators and devices. Rawinsert usage in code:

Future<int> insertUser(UserModel sqluser) async {
Database db = await database;
return await db.rawInsert(
    'INSERT INTO $loginTable($colEmailId, $colPassword ,$colloginDateTime) VALUES(?,?,?)',
    [
      sqluser.email,
      sqluser.password,
      DateTime.now().toUtc().toString(),
    ]);
}