Transactions

Transactions are useful when you want to perform multiple operations. With Flat you have two options to start a transaction:

1. Inside a DAO:

   You can annotate a method with @transaction and make that method async. Also you have to await for every database call you make inside that method.

   @transaction
   Future<void> replacePersons(List<Person> persons) async {
     await deleteAllPersons();
     await insertPersons(persons);
   }
   

2. On database:

   You can call transaction on your database with a callback which will get called whenever transaction created with a database object for you to do your operations on. Again it's required to await for every database call.

   await database.transaction<void>((dynamic db) async {
     if (db is AppDatabase) {
       await db.personDao.deleteAllPersons();
       await db.personDao.insertPersons(persons);
     }
   });
   

Attention

• Transactions can return objects