sqlite "like" syntax didn't bring any results

I try to read from the sqlitDB with the following query:

public ArrayList<ReminderNote> getAllRegexItems(String author) {
 ArrayList<ReminderNote> results = new ArrayList<>();

    Cursor cursor = this.getReadableDatabase().query(
            REMINDER_NOTE_TABLE,
            new String[]{KEY_ID, KEY_NOTE, KEY_AUTHOR}, Strings.isEmpty(author) ? null : KEY_AUTHOR + " = ?",
            Strings.isEmpty(author) ? null : new String[]{"%" + author + "%"}, null, null, null);

is it OK to use the % like i did?

If author is null or empty I want all the results to be fetched.

Unfortunately I get empty results set even though I added such entity beforehand.

and I can see non-empty results set when I execute:

Cursor cursor = this.getReadableDatabase().query(
            REMINDER_NOTE_TABLE,
            new String[]{KEY_ID, KEY_NOTE, KEY_AUTHOR}, null, null, null, null, null);