CODEWITHSUNDEEP
javaandroidfirebasefirebase-realtime-database
Thilo Jaeggi
Thilo Jaeggi

Reputation: 87

Delete all Database entries with certain key

I have followers in my app. If someone follows someone it creates a new entry for the user that is being followed with a child containing the User ID of the follower. This is how my structure looks like

If an User deletes their account I want that all entries of their User ID gets deleted. Is this possible?

Upvotes: 1

Views: 130

Answers (3)

Rushikesh Gaikwad
Rushikesh Gaikwad

Reputation: 125

If the user deletes the account then its UID should be deleted from the whole firebase data structure so you can do the following: If the user which is going to delete its account is logged in then do following: You can give a Button named Delete Account and implement following piece of code on onclicklistener of that Button. 

FirebaseUser user = FirebaseAuth.getInstance().getCurrentUser();
DatabaseReference followRef = FirebaseDatabase.getInstance().getReference().child("Follow").child(user.getUid()).child("following");
followRef.addValueEventListener(new ValueEventListener() {
        @Override
        public void onDataChange(@NonNull DataSnapshot dataSnapshot) {

            for (DataSnapshot data : dataSnapshot.getChildren()) {
                //Getting User id from dataSnapshot
                String userid = data.getValue(String.class);
                DatabaseReference Ref = FirebaseDatabase.getInstance().getReference().child("Follow").child(userid).child("followers").child(user.getUid());
                Ref.removeValue();
             }
        }

        @Override
        public void onCancelled(@NonNull DatabaseError databaseError) {

            Log.i(TAG, "onCancelled: Error: " + databaseError.getMessage());

        }
    });

    DatabaseReference followRef1 = FirebaseDatabase.getInstance().getReference().child("Follow").child(user.getUid());
    followRef1.removeValue();

    DatabaseReference followRef2 = FirebaseDatabase.getInstance().getReference().child("Users").child(user.getUid());
    followRef2.removeValue();

If any Query then please let me know Thank You.

Upvotes: 1

Hasan Bou Taam
Hasan Bou Taam

Reputation: 4035

I assume you want to remove the UID of the follower from any possible followed user:

If that is what you want, then you have to read the Follow node, and remove any possible existance of the follower UID:

//the user ID

String userID = FirebaseAuth.getInstance().getCurrentUser().getUid();

//the main reference node "Follow"

DatabaseReference mDatabase = FirebaseDatabase.getInstance().getReference().child("Follow");


//read the node and loop through all UIDs

ValueEventListener listener = new ValueEventListener() {
    @Override
    public void onDataChange(DataSnapshot dataSnapshot) {

     //loop through all UIDs under "Follow" and remove the user ID that deleted his/here account from "followers"

     for(DataSnapshot ds : dataSnapshot.getChildren()){

       if(ds.child("followers").child(userID).exists()){

         ds.child("followers").child(userID).getRef().removeValue();

       }
     }

    }

    @Override
    public void onCancelled(DatabaseError databaseError) {

        Log.w(TAG, "loadPost:onCancelled", databaseError.toException());

    }
};
mDatabase.addValueEventListener(listener);

Upvotes: 1

Peter Haddad
Peter Haddad

Reputation: 80924

To delete the key, try the following:

FirebaseUser user = FirebaseAuth.getInstance().getCurrentUser();
DatabaseReference followRef = FirebaseDatabase.getInstance().getReference().child("Follow");
followRef.child(user.getUid()).removeValue();

Get the currently logged in user, and then call removeValue() to delete the node.

Upvotes: 0

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