CODEWITHSUNDEEP
javaandroidfirebasefirebase-realtime-database
Jameel Ahmad
Jameel Ahmad

Reputation: 33

how use where query in firebase data base android java

I want to Update the All Students of class where classection=Six:B Which Query I can use please Guide there Are many students I want to update All the student of six class at the same time.

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Upvotes: 0

Views: 43

Answers (1)

Alex Mamo
Alex Mamo

Reputation: 138824

I want to Update the All Students of class where classection=Six:B

To achieve that, you need to use a Query to filter the students based on the "classection" property. To also perform an update, for example, to change the value from "Six:B" to "Six:C", please see use the following lines of code:

DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();
DatabaseReference studentsRef = rootRef.child("Students");
Query classSectionQuery = studentsRef.orderByChild("classection").equalTo("Six:B");
classSectionQuery.get().addOnCompleteListener(new OnCompleteListener<DataSnapshot>() {
    @Override
    public void onComplete(@NonNull Task<DataSnapshot> task) {
        if (task.isSuccessful()) {
            for (DataSnapshot ds : task.getResult().getChildren()) {
                ds.child("classection").getRef().setValue("Six:C");
            }
        } else {
            Log.d(TAG, task.getException().getMessage()); //Don't ignore potential errors!
        }
    }
});

The result of this code will be the update of all students "WHERE" classection is equal to "Six:B".

Upvotes: 1

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