CODEWITHSUNDEEP
javaandroidfirebasefirebase-realtime-database
Arman Abdullin
Arman Abdullin

Reputation: 31

How to remove from firebase?

getReference ("Posts"). child (postKey) .child ("date") where the date is written in "date" (which will be in the future, for example, April 30, 2020 in String format). I want to write a program that will take place "Post" to get the whole date, and if the current date and date from "Post" (currentDate == date ("Post")) then delete this post. How to get everything from the list for comparison?

enter image description here

I added the code where I add "Post". I get the date from calendarView so conveniently it is written in Russian language

private void deletePostFromFirebase(){
    SimpleDateFormat simpleDateFormat = new SimpleDateFormat("dd MMM yyyy", Locale.ENGLISH);
    Date date = new Date();
    String newDate = simpleDateFormat.format(date);
    DatabaseReference ref = FirebaseDatabase.getInstance().getReference("Posts");
    ref.orderByChild("date").equalTo(newDate).addListenerForSingleValueEvent(new ValueEventListener() {
        @Override
        public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
            for (DataSnapshot itemSnapshot: dataSnapshot.getChildren()) {
                itemSnapshot.getRef().removeValue();
            }
        }

        @Override
        public void onCancelled(@NonNull DatabaseError databaseError) {
            throw databaseError.toException();
        }
    });
}

Upvotes: 1

Views: 46

Answers (1)

Peter Haddad
Peter Haddad

Reputation: 80914

If you want to delete the date according to a condition, then you can do the following:

DatabaseReference ref = FirebaseDatabase.getInstance().getReference("Posts");
ref.orderByChild("date").equalTo(date).addListenerForSingleValueEvent(new ValueEventListener() {
        @Override
        public void onDataChange(DataSnapshot dataSnapshot) {
          for(DataSnapshot ds : dataSnapshot.getChildren()){
            String key = ds.getKey();
            ref.child(key).child("date").removeValue();
          }
        }

        @Override
        public void onCancelled(DatabaseError databaseError) {

        }
    });

Perform a query orderByChild("date").equalTo(date) then you can iterate and retrieve the key and delete the child date.

Upvotes: 1

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