import 'package:floor/floor.dart';
@Entity(tableName: 'EventN') // Use @Entity instead of @entity
class EventN {
@PrimaryKey(autoGenerate: true)
final int? id;
final DateTime date;
final String description;
final String category;
final String subCategory;
final String mdp;
final double? amount;
final String type;
final String mdpType;
final String? mdpName;
EventN({this.id, required this.date, required this.description, required this.category, required this.amount, required this.type, required this.subCategory,required this.mdp, required this.mdpType, this.mdpName });
}
And a EventDao:
import 'package:floor/floor.dart';
import '../entity/event.dart';
@dao
abstract class EventDao {
@Query('SELECT * FROM EventN')
Stream<List<EventN>> findAllEvent();
@Query('SELECT (SUM(CASE WHEN type = \'entrata\' THEN amount ELSE 0 END) - '
'SUM(CASE WHEN type = \'uscita\' THEN amount ELSE 0 END)) AS net_result '
'FROM EventN')
Stream<double?> calculateNetResult();
@insert
Future<void> insertEventN(EventN event);
}
The problem is that when my table is empty, my query of calculate net_result gives error as Unhandled Exception: type 'Null' is not a subtype of type 'double' in type cast
I shouldn't use databaseview in this case because it's a single result query right?
Hi.
I have a Event Entity:
And a EventDao:
The problem is that when my table is empty, my query of calculate net_result gives error as Unhandled Exception: type 'Null' is not a subtype of type 'double' in type cast I shouldn't use databaseview in this case because it's a single result query right?