Nsryjdtyk

I am faceing some issues with compile time errors from the Room Library.

I am using Version: 2.1.0-alpha02

The following Dao causes the error:

@Dao()

public interface WorkoutExerciseDao {



    [......]

    @Update()

    Single<Integer> updateWorkout(final WorkoutExercise... workoutExercises);





    @Delete

    Single<Integer> deleteWorkouts(final WorkoutExercise... user);



    @Query("DELETE FROM workout_exercise_table WHERE id  IN(:exerciseIds)")

    Single<Integer> deleteWorkouts(final long... exerciseIds);

}

Currently the first @Delete annotated Method compiles fine and works as expected. If I add the second one(Delete inside the query method) it breaks compilation with an error:

Deletion methods must either return void or return int (the number of
deleted rows).

Do I miss something here?

you are right and I had this problem. I don't know reason but I know there isn't any way in latest version of room to handle this problem and when you use query for DELETE it says return type must be void or int but if you want use RX for DELETE query you can do like this but maybe not best way:
first convert interface to abstract class and also all methods to abstract method then

@Dao

public abstract class WorkoutExerciseDao {



    @Update()

    abstract Single<Integer> updateWorkout(final WorkoutExercise... workoutExercises);



    @Delete

    abstract Single<Integer> deleteWorkouts(final WorkoutExercise... user);



    @Query("DELETE FROM workout_exercise_table WHERE id  IN(:exerciseIds)")

    abstract Integer deleteWorkouts(final long... exerciseIds);



    Single<Integer> deleteWorkoutsById(final long... exerciseIds) {

        return Single.create(emitter -> {

            emitter.onSuccess(deleteWorkouts(exerciseIds));

        });

    }

}

You need to use AndroidX

Migrate your project to AndroidX first refer to the documentation, the easy way is to right click your project folder make sure it is in projects perspective, right click the folder and click Refactor and there should be an option "Migrate to AndroidX".

After migrating your project to AndroidX you can now add the AndroidX dependencies in your app level gradle.

implementation "androidx.room:room-runtime:$room_version"

annotationProcessor "androidx.room:room-compiler:$room_version" // kapt for Kotlin

// optional - RxJava support for Room

implementation "androidx.room:room-rxjava2:$room_version"

See the documentation for adding latest version dependencies for Room.