How do I fix "Future not a type" error in flutter?

Question

I was creating a database in flutter and I unknowingly added ~/.dartServer/.analysis-driver/ to my program. The complier now shows "Future not a type" with red line beneath. Here is the code for ref :

import 'package:sqflite/sqflite.dart';
import 'package:path_provider/path_provider.dart';
import 'package:path/path.dart';
import 'dart:io';

class Db_Help{

  static final _db_name="Work_tasks.db";
  static final _db_version=1;
  static final table="Work Table";

  static final task_id="ID";
  static final task="Task";
  static final bool_check="Value";

  static Database _database;

  Db_Help._private_cons();
  static final Db_Help instance=Db_Help._private_cons();

  _initDatabase() async{
    Directory docu_dir=await getApplicationDocumentsDirectory();
    String path=join(docu_dir.path,_db_name);

    return await openDatabase(path, version: _db_version, onCreate: _onCreate);
  }

  Future<Database> get database async{

    if(_database!=null)
      return _database;

    _database=await _initDatabase();
    return _database;

  }

  Future _onCreate(Database db, int version) async{
    await db.execute('''
    CREATE TABLE $table (
    $task_id INTEGER PRIMARY KEY,
    $task TEXT NOT NULL,
    $bool_check INTEGER)
    ''');
  }

  Future<int> insert(Map<String,dynamic> row) async{
    Database db= await instance.database;
    return await db.insert(table, row);
  }

 }

Can Someone help in removing ~/.dartServer/.analysis-driver/ (which is probably the root cause) ? I don't know how to remove that.

Thanks in advance :)

Answer 1

You need to change the return type of your onCreate function. It should be void instead of Future.

void _onCreate(Database db, int version) async{
  await db.execute('''
  CREATE TABLE $table (
  $task_id INTEGER PRIMARY KEY,
  $task TEXT NOT NULL,
  $bool_check INTEGER)
  ''');
}