Updating a property in a transaction does not work

[fvisticot]

The following code never complete the RES1 step and no exception is fired

try {
      await _db.transaction((txn) async {
        StoreRef storeRef = intMapStoreFactory.store(kBeaconsStore);

        for (final rec in records) {
          final record = storeRef.record(int.parse(rec.id));
          if (await record.exists(_db)) {
            final res = await record.get(_db);
            print("RES: $res");
            final res1 = await record.update(_db, {'isFlushed': true});
            print("RES1: $res1");
          } else {
            print("Record with id ${rec.id} not found");
          }
        }
      });
    } catch (e) {
      throw BeaconLocationStoreException('[markRecordsAsFlushed] $e');
    }

This code is working (removing the transaction)

StoreRef storeRef = intMapStoreFactory.store(kBeaconsStore);
    for (final rec in records) {
      final record = storeRef.record(int.parse(rec.id));
      if (await record.exists(_db)) {
        final res = await record.get(_db);
        print("RES: $res");
        final res1 = await record.update(_db, {'isFlushed': true});
        print("RES1: $res1");
      } else {
        print("Record with id ${rec.id} not found");
      }
    }

[alextekartik]

Yes that is a deadlock, since you are trying to use the database in a transaction rather than using the transaction itself. See a note about that here:
https://github.com/tekartik/sembast.dart/blob/master/sembast/doc/transactions.md#dead-lock

basically you should not do:

final res = await record.get(_db);

but

final res = await record.get(txn);