Android Room - Get the id of new inserted row with auto-generate

Solution 1:

Based on the documentation here (below the code snippet)

A method annotated with the @Insert annotation can return:

• long for single insert operation
• long[] or Long[] or List<Long> for multiple insert operations
• void if you don't care about the inserted id(s)

Solution 2:

@Insert function can return void, long, long[] or List<Long>. Please try this.

 @Insert(onConflict = OnConflictStrategy.REPLACE)
  long insert(User user);

 // Insert multiple items
 @Insert(onConflict = OnConflictStrategy.REPLACE)
  long[] insert(User... user);

Solution 3:

The return value of the insertion for one record will be 1 if your statement successfully.

In case you want to insert list of objects, you can go with:

@Insert(onConflict = OnConflictStrategy.REPLACE)
public long[] addAll(List<Object> list);

And execute it with Rx2:

Observable.fromCallable(new Callable<Object>() {
        @Override
        public Object call() throws Exception {
            return yourDao.addAll(list<Object>);
        }
    }).subscribeOn(Schedulers.io()).observeOn(AndroidSchedulers.mainThread()).subscribe(new Consumer<Object>() {
        @Override
        public void accept(@NonNull Object o) throws Exception {
           // the o will be Long[].size => numbers of inserted records.

        }
    });

Solution 4:

Get the row ID by the following sniplet. It uses callable on an ExecutorService with Future.

 private UserDao userDao;
 private ExecutorService executorService;

 public long insertUploadStatus(User user) {
    Callable<Long> insertCallable = () -> userDao.insert(user);
    long rowId = 0;

    Future<Long> future = executorService.submit(insertCallable);
     try {
         rowId = future.get();
    } catch (InterruptedException e1) {
        e1.printStackTrace();
    } catch (ExecutionException e) {
        e.printStackTrace();
    }
    return rowId;
 }

Ref: Java Executor Service Tutorial for more information on Callable.