Getting output as "Instance of 'Future<dynamic>'" in flutter

Question

I am trying get sum of a column in sqlite table using Bloc pattern.

debt_bloc.dart

getTotalAmount() async {
    return await _debtRepository.getTotalAmt();
  }

debt_dao.dart

 Future<int> getTotalAmount() async {
    final db = await dbProvider.database;

    var result = await db.rawQuery("SELECT SUM(amount) FROM $debtDetailsTable");
    int value = result[0]["SUM(amount)"];
    return value;
  }

debt_repositary.dart

Future getTotalAmount() => debtDao.getTotalAmount();

When i try to print like below

var total;
   @override
    void initState () {
      super.initState();
     _asyncMethod();
    }

    _asyncMethod() async {
      var t = await debtBloc.getTotalAmount();
      setState(() {
        total = t;
      });
    }

    print(total);

Output not updating when add new data. But if go back to home screen and come to respective screen value is updating.

Please guide me in right way. Thanks in advance

CopsOnRoad · Accepted Answer · 2019-11-01 10:22:15Z

1

Await on your method first before printing it.

var total = await debtBloc.getTotalAmount(); // await here
print(total); // should now print some int value

answered Nov 1, 2019 at 10:22

CopsOnRoad

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8 Comments

Nagaraj Over a year ago

Now that is solved but output value is "null". I am new to flutter dn't know how null is coming. Trying to fix it, If you have any idea about it, help me out.

Nagaraj Over a year ago

While tried to print in debt_dao.dart. var result = await db.rawQuery("SELECT SUM(amount) FROM $debtDetailsTable"); print(result); output comes correct.

CopsOnRoad Over a year ago

What int value = result[0]["SUM(amount)"]; prints?

Nagaraj Over a year ago

It prints sum of amount column value. Ex. 30000

CopsOnRoad Over a year ago

@Nagaraj I understand what it should print but can you tell me what exactly the current value prints.

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