How do I retrieve and list data from join table to recyclerview in firebase?

Question

This is the structure of my database.

Restaurant Adapter

DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference().child("Restaurant");
DatabaseReference infoRef = rootRef.child("Info");
DatabaseReference categoryRef = rootRef.child("Category");

    FirebaseRecyclerOptions <RestaurantDetails> options = new FirebaseRecyclerOptions.Builder<RestaurantDetails>()
                                                      .setIndexedQuery(infoRef, categoryRef, RestaurantDetails.class)
                                                      .build();

    adapter = new RestaurantAdapter(options);
    recyclerView.setAdapter(adapter);

I am using this format from this link on the structured data. When I did a quick test, the page shows empty. Also, I like to ask if I want to join another table called "Location" as can see from image. Would like to know how cause I believe I only can join 2?

https://firebase.google.com/docs/database/admin/structure-data

UPDATED Am I on the right track? It didn't work and I got another new error which is this:

com.google.firebase.database.DatabaseException: Can't convert object of type java.lang.Boolean to type com.isaac.foodie.RestaurantDetails

AND THIS

2020-04-05 21:19:59.149 3490-3490/com.isaac.foodie E/AndroidRuntime: at android.view.ViewGroup.layout(ViewGroup.java:6594)

Have you tried to do something like this `rootRef.child("Category").child("Restaurant");` — Ticherhaz FreePalestine, Apr 05 '20 at 12:50
I have tried but I put it another way which is Restaurant then Category. May I know why Category and then Restaurant? — I.Z., Apr 05 '20 at 13:05
First parameter is keyQuery - the Firebase location containing the list of keys to be found in dataRef 2nd parameter is dataRef - the Firebase location to watch for data changes. Each key found at keyRef's location represents a list item. You can refer to this link https://github.com/firebase/FirebaseUI-Android/tree/master/database — Ticherhaz FreePalestine, Apr 05 '20 at 13:10
I have tried your method and it did not work or maybe I have done something wrong. Please look at the post. I have updated it — I.Z., Apr 05 '20 at 13:25
It didn't show which line for the error. Also, would like to clarify, if I want to continue with this format. Will I be getting the result of the name or the boolean, "True"? Because I want to retrieve the name not the boolean — I.Z., Apr 05 '20 at 14:02
btw if you want to display all the children from the root `Info` , you can use the simple one — Ticherhaz FreePalestine, Apr 05 '20 at 14:56
I have done that earlier from the very start before I make this new changes. Because I want to filter by tag, I have to use one of this format. This is where I'm stuck in. Again, to clarify before I continue this, will I get the result true or the category name? I am a newbie to programming so I am learning as I go — I.Z., Apr 05 '20 at 15:02
I would suggest you can add a property called `category`. so can query by it — Ticherhaz FreePalestine, Apr 05 '20 at 15:05
Maybe you misunderstood my previous comment, before I made changes to the DB structure. It was all in one flat tree which was in everything including category and location. When I do the query, it repeated the value of category like cafe, cafe. I want to do it SELECT DISTINCT but Firebase does not play that way. — I.Z., Apr 05 '20 at 15:13
I want to retrieve the data something like this but I use this format. Should I change to the one like in the link below? https://stackoverflow.com/questions/35170616/firebase-and-select-distinct — I.Z., Apr 05 '20 at 15:52

How do I retrieve and list data from join table to recyclerview in firebase?

0 Answers0