firebase query how can i retrieve two specific values from child

Question

i use recyclerview to retrieve a chat messages and i am wondering if there is method to retrieve two different values i mean something like this :

FirebaseRecyclerOptions<enchat> options = 
    new FirebaseRecyclerOptions.Builder<enchat>()
        .setQuery(
            mChatDatabase.orderByChild("state").equalTo("sent")
            && mChatDatabase.orderByChild("state").equalTo("received"),
         enchat.class)
        .build();

score 1 · Accepted Answer · answered Sep 22 '20 at 21:58

There is no way to pass two values into a condition. Firebase Realtime Database doesn't support this type of OR condition.

Also see:

The common workarounds are:

Perform two queries and merge the results in your application code. But you won't be able to use the adapters from FirebaseUI as is in that case.
Perform a range query, but this only works if there are no state values between received and sent. If that is the case, the query could be:
```
mChatDatabase.orderByChild("state").startAt("received").endAt("sent")
```
Add an additional property that is true when the state is either received or sent and filter on that:
```
mChatDatabase.orderByChild("stateIsReceivedOrSent").equalTo(true)
```

firebase query how can i retrieve two specific values from child

1 Answers1