flutter with Sqflite : The return type 'Null' isn't a 'Future<_>', as required by the closure's context

Question

I have a problem function of Inserted => The return type 'Null' isn't a 'Future<_>', as required by the closure's context

Answer 1

You have to add async to your function.

await database.transaction((txn) async { });

I would also replace then / catchError inside the function with await and try/catch.