Unique constraint failed room database android

Question

I\'m facing a problem with Room database, when trying to use insert method that I declared in Dao Class to write a data into database this error shows up:

Answer 1

AppDatabase Class

@Database(entities = {Task.class}, version = 1, exportSchema = false)
public abstract class AppDatabase extends RoomDatabase {
    public abstract TaskDao mTaskDao();
}

Model Class

@Entity
public class Task {

    @PrimaryKey(autoGenerate = true)
    private int uid;

    @ColumnInfo(name = "task_name")
    private String mName;

    @ColumnInfo(name = "task_box")
    private Integer mBox;

    @ColumnInfo(name = "is_done")
    private Integer mIsDone;
}

Answer 2

I figure it out, that error because there is no unique value in data (in primaryKey) so I make it auto generated,

Model Class

@Entity
public class Task {
    @PrimaryKey(autoGenerate = true)
    private int uid;
    ...
}