Firestore perform delete based on condition

Question

Is there a way I can perform a delete on Firestore documents where field1 =x and field2 = y?

I see the delete function

Answer 1

To achieve this, you need to create the desired query first and then just use the delete() method like this:

FirebaseFirestore rootRef = FirebaseFirestore.getInstance();
CollectionReference itemsRef = rootRef.collection("yourCollection");
Query query = itemsRef.whereEqualTo("field1", "x").whereEqualTo("field2", "y");
query.get().addOnCompleteListener(new OnCompleteListener<QuerySnapshot>() {
    @Override
    public void onComplete(@NonNull Task<QuerySnapshot> task) {
        if (task.isSuccessful()) {
            for (DocumentSnapshot document : task.getResult()) {
                itemsRef.document(document.getId()).delete();
            }
        } else {
            Log.d(TAG, "Error getting documents: ", task.getException());
        }
    }
});

Answer 2

Here's my method for both querying and deleting documents from firestore. First it queries the data, then it deletes it. Note, this method must be adapted for integer/double values.

    public void whereQueryDelete(final String collection, final String field, final String value) {
    mFirestoreDatabase.collection(collection)
            .whereEqualTo(field, value)
            .get()
            .addOnCompleteListener(new OnCompleteListener<QuerySnapshot>() {
                @Override
                public void onComplete(@NonNull Task<QuerySnapshot> task) {
                    if (task.isSuccessful()) {
                        for (QueryDocumentSnapshot document : task.getResult()) {
                            Log.d(TAG, document.getId() + " => " + document.getData());
                            String idDelete = document.getId();
                            mFirestoreDatabase.collection(collection).document(idDelete)
                                    .delete()
                                    .addOnSuccessListener(new OnSuccessListener<Void>() {
                                        @Override
                                        public void onSuccess(Void aVoid) {
                                            Log.d(TAG, "DocumentSnapshot successfully deleted!");
                                        }
                                    })
                                    .addOnFailureListener(new OnFailureListener() {
                                        @Override
                                        public void onFailure(@NonNull Exception e) {
                                            Log.w(TAG, "Error deleting document", e);
                                        }
                                    });
                        }
                    } else {
                        Log.d(TAG, "Error getting documents: ", task.getException());
                    }
                }
            });
}