SQLite error "near "#gmail": syntax error "flutter - sql

Question

Here's the error I get:
E/SQLiteLog(25090): (1) near "#gmail": syntax error .
It seems like there is a problem in email input.
I guess there is nothing wrong in the creating of database.
creating db:
class UsersTable {
static const String tableName = 'Users';
static const String id = 'id';
static const String email = 'email';
static const String createQuery = '''
CREATE TABLE IF NOT EXISTS $tableName (
$id integer primary key autoincrement,
$email text not null unique);''';
}
in model class:
class Users {
late final int id;
late String email;
Users({
required this.id,
required this.email,
});
Users.fromDb(Map<String, dynamic> map) {
id = map[UsersTable.id];
email = map[UsersTable.email];
}
}
in UserService class which I think is where the problem arise:
class UserService {
...
Future<Users> getOrCreateUser({
required String email,
bool setAsCurrentUser = true,
}) async {
try {
//we found the user
final user = await getUser(email: email);
if (setAsCurrentUser) {
_user = user;
}
return user;
} on CouldNotFindUser {
//we didn't find the user
final createdUser = await createUser(email: email);
if (setAsCurrentUser) {
_user = createdUser;
}
return createdUser;
} catch (e) {
rethrow;
}
}
Future<Users> getUser({required String email}) async {
await _ensureDbIsOpen();
final db = _getDatabaseOrThrow();
final results = await db.query(
UsersTable.tableName,
limit: 1,
where: 'email = ?',
whereArgs: [email.toLowerCase()],
);
if (results.isEmpty) {
throw CouldNotFindUser();
} else {
return Users.fromDb(results.first);
}
}
...}
in main class:
...
Widget build(BuildContext context) {
return FutureBuilder(
future: _userService.getOrCreateUser(email: userEmail),
builder: (context, snapshot) {
return Provider(
create: (ctx) => HomePageController(),
dispose: (ctx, HomePageController controller) =>
...
how can I solve this error?