How to remove values in firebase

Question

Just a little question :
Now i have this structure

images
---- uniqueId
-------- id_logement : 1747657
-------- image : dataimage
---- uniqueId         


        

Answer 1

Try this code:-

 rootRef.child("images").addListenerForSingleValueEvent(new ValueEventListener() {
        @Override
        public void onDataChange(DataSnapshot snapshot) {
            for(DataSnapshot dataSnapshot :  snapshot.getChildren())
            {
               if(dataSnapshot.child("id_logement").getValue().toString().equals("1747657"))
               {
                   dataSnapshot.getRef().setValue(null);
               }
            }           
        }
        @Override
        public void onCancelled(FirebaseError firebaseError) {
        }
    });

Answer 2

There is actually an easier way.

Just call the ref property in your snapshot, and use .on('child_added',...)

var ref = firebase.database().ref('images');
ref.orderByChild('id_logement').equalTo(key).on('child_added', (snapshot) => {
     snapshot.ref.remove()
});

Answer 3

Since you want to bulk delete data based on a query, you will need to retrieve it first and delete it setting its values to null and committing the changes with update.

const ref = firebase.database().ref('images');
ref.orderByChild('id_logement').equalTo(key).once('value', snapshot => {
     const updates = {};
     snapshot.forEach(child => updates[child.key] = null);
     ref.update(updates);
});

Working jsFiddle.