How to fetch data from firebase?

Question

I need to fetch the dish name from menu table based on the restaurantID in the restaurant table. Mt database structure:

Being new to firebase, I'm not able to find the starting point on how to query through the data.

From your above structure it seems clear that your resraurant id of restaurant table is same as your menu id of menu table. — Prajwal Waingankar, Jan 01 '20 at 05:31
Yes.. restaurant and menu are 2 different tables.. restaurantID generated in restaurant table is related to the menu table.. restaurantID and dishID are different — Mayur Sadhu, Jan 01 '20 at 05:35
You have add one field in `restaurants id` in every `dishes`.And `restaurants id` is string that contain multiple restaurants ids just like this `restaurant1,restaurant2,`. — Rahul sharma, Jan 01 '20 at 05:40
I hope it'll help you : https://stackoverflow.com/a/35932786 — Viral Patel, Jan 01 '20 at 06:00
What is the key `-LxSiDXHCXM7pMDdwPJA`? Is this a user ID? How do you get it's value? — samthecodingman, Jan 01 '20 at 07:50
What have you tried so far in code? Please also respond with @AlexMamo — Alex Mamo, Jan 01 '20 at 15:11

score 0 · Answer 1 · answered Jan 01 '20 at 06:05

Add one field in restaurants id in every dishes. Then create the Class model for Dish.

Now fetch dish data from Firebase.

mFirebaseRef = new Firebase(FIREBASE_URL);
List<Dish_Model> list=new ArrayList();
mFirebaseRef.addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
    for (DataSnapshot postSnapshot : dataSnapshot.getChildren()) {
           Dish_Model dish= postSnapshot.getValue(Dish_Model.class);
           list.add(dish);// here you will get All dish data from firebase
       }
}

@Override
public void onCancelled(FirebaseError firebaseError) {

}
 });

At last You need filter data as per restaurants id Suppose you have String restaurants_id="xcnvkncxvkjnxj". Create list for restaurant dishes

  List<Dish_Model> restaurant_dishes=new ArrayList();
  for(Dish_Model  dish:list)
   {
    String[] separated = restaurants_id.split(",");
       for (String id:separated )
         {
           if(id==restaurants_id)
              {
               /*if current dish contain restaurants id then dish will add in 
                  restaurant dishes*/
               restaurant_dishes.add(dish);
                break;
                /*then we break the loop bcoz same dish will not have multiple same 
                 restaurants_id*/
               }
         }
    }

That's done. restaurant_dishes contain all the dishes of restaurant.

How to fetch data from firebase?

1 Answers1