Firebase 删除值

Question

I'm developing an app with Android Studio using Firebase. I want to delete a certain date but when I click on the delete button it does nothing. I can't reach to parent because it's a generated key. Any help would be appreciated.

private void deleteDate(){
    String dateValue = showDate.getText().toString();

    FirebaseUser user = FirebaseAuth.getInstance().getCurrentUser();
    String userid = user.getUid();

    DatabaseReference usersRef = FirebaseDatabase.getInstance().getReference().child("Users").child(userid).child("smokeFreeDays");

    usersRef.addListenerForSingleValueEvent(new ValueEventListener() {
        @Override
        public void onDataChange(@NonNull @NotNull DataSnapshot snapshot) {
            for (DataSnapshot userDataSnapshot : snapshot.getChildren()) {
                String date = userDataSnapshot.getValue(String.class);
                if (date.equals(dateValue)) {
                    snapshot.getRef().child(dateValue).removeValue();
                } else if (!date.equals(dateValue)) {
                    snapshot.getRef().child(dateValue).removeValue();
                }
            }
        }

        @Override
        public void onCancelled(@NonNull @NotNull DatabaseError error) {
            Log.w("tag", "loadPost:onCancelled", error.toException());
        }
    });
}

My Database:

Answer 1

See my comment above for debugging the issue.

But as an overall hint, I'd recommend reconsidering the data structure under smokeFreeDays to look like this:

"smokeFreeDays": {
  "2021-05-09": true,
  "2021-05-10": true
}

The two changes in this structure:

• The date format is now ordered year-month-day , which is better suited for querying. For example, you can get all smoke free days in 2021 with: usersRef.orderByKey().startAt("2021-").endAt("2021~") .
• We now use the date as the key, which means we no longer have to load all smokeFreeDays to find the value to delete. You can now delete the node once you know the date with: usersRef.child("2021-05-09").removeValue() .