CODEWITHSUNDEEP
androidfirebasefirebase-realtime-database
Dharmik
Dharmik

Reputation: 61

How to delete data from firebase android

I faced an issue when I had to delete that data which user entered in here this photo. If the user entered enrollment number 60 then I have to delete all data from marks where the enrollment number is 60.

enter image description here

It deletes the data which user entered and it verifies that enrollment from marks and delete all data where enrollment is 66 it means delete that document or node.

I tried the following that did not work.

reff.child("Marks").removeValue().equals(et1);

Upvotes: 1

Views: 2423

Answers (3)

Dharmik
Dharmik

Reputation: 61


    String et1 =e1.getText().toString().trim();
                    reff.child("Marks").orderByChild("enrollment").equalTo(et1)
                            .addListenerForSingleValueEvent(new ValueEventListener() {
                                @Override
                                public void onDataChange(@NonNull DataSnapshot dataSnapshot)
                                {
                                    for (DataSnapshot ds : dataSnapshot.getChildren())
                                    {
                                        ds.getRef().removeValue();
                                        Toast.makeText(getApplicationContext(), "Deleted", Toast.LENGTH_SHORT).show();
                                    }
                                }

                                @Override
                                public void onCancelled(@NonNull DatabaseError databaseError)
                                {
                                    Toast.makeText(getApplicationContext(), "Failed to delete", Toast.LENGTH_SHORT).show();
                                }
                            });

Upvotes: 0

mufazmi
mufazmi

Reputation: 1210

Try this code.

int enrollmentId = Integer.parseInt( et1.getText().toString() );
reff.child("Marks").orderByChild("enrollment").equalTo(enrollmentId)
.addListenerForSingleValueEvent(new ValueEventListener() {
                @Override
                public void onDataChange(@NonNull DataSnapshot dataSnapshot) 
                {
                    for (DataSnapshot ds : dataSnapshot.getChildren())
                    {
                        ds.getRef().removeValue(); 
                        Toast.makeText(context, "Deleted", Toast.LENGTH_SHORT).show();
                    }
                }

                @Override
                public void onCancelled(@NonNull DatabaseError databaseError) 
                {
                    Toast.makeText(context, "Failed to delete", Toast.LENGTH_SHORT).show();
                }
                });

Upvotes: 1

Peter Haddad
Peter Haddad

Reputation: 80914

To delete data do the following:

DatabaseReference data = FirebaseDatabase.getInstance().getReference().child("Marks");
data.orderByChild("enrollment").equalTo("66").addListenerForSingleValueEvent(new ValueEventListener() {
         @Override
      public void onDataChange(DataSnapshot dataSnapshot) {
      for(DataSnapshot data: dataSnapshot.getChildren()){
            data.getRef().removeValue();

                  }

            }
        @Override
       public void onCancelled(DatabaseError databaseError) {

               }
          });

Add a reference to child Marks then using the query orderByChild you can get the correct node and delete it

Upvotes: 1

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