SELECT username, COUNT(username)
FROM users
GROUP BY username
HAVING COUNT(username) > 1;
This query will identify usernames that appear more than once in the table. However, please note that removing duplicates should be done with caution and will depend on your specific database management system. You may need to create a backup of your data before removing duplicates.
Additionally, if you have a specific SQL task or code example you'd like to inquire about, feel free to provide more details, and I can assist you further.
