How to delete all documents in collection in Fires

Question

This question already has an answer here:

• Deleting all documents in Firestore collection 3 answers
• How to model this structure to handle delete 1 answer

I need to delete all documents in collection by clicking a button. But Firestore guide doesn't say how to delete ALL the files.

For example.

          public void onClick(View view) {
//                movieList.clear();
                WriteBatch batch = db.batch();
                Movie movie = new Movie(subj.getText().toString(), cab.getText().toString());
                movieList.add(movie);
                mAdapter.notifyDataSetChanged();
                DocumentReference nycRef = db.collection("Users").document();
                batch.set(nycRef, new Movie(subj.getText().toString(), cab.getText().toString()));
                batch.commit().addOnCompleteListener(new OnCompleteListener<Void>() {
                    @Override
                    public void onComplete(@NonNull Task<Void> task) {


// ...
                    }

This is part of my MainActivity file.

When adding a file, it pushes info to Firestore

But I also need to delete files(all)

P.S I always have less than 9 files in collection

P.P.S I've googled it, nothing found.

Answer 1

Firestore doesn't provide any API to delete all documents in a collection. What you'll have to do is query for all the documents, collect all of their IDs, then write some code to iterate those IDs and delete all of them.