This query will give us John, Sam, Tom, Tom because they all have the same email.
However, what I want is to get duplicates with the same email and name.
That is, I want to get "Tom", "Tom".
There are many ways to do this,
one of them below,
SELECT a.*
FROM users a
JOIN (SELECT username, email, COUNT(*)
FROM users
GROUP BY username, email
HAVING count(*) > 1 ) b
ON a.username = b.username
AND a.email = b.email
ORDER BY a.email
This might help: FInd duplicates (https://chartio.com/learn/databases/how-to-find-duplicate-values-in-a-sql-table/)
Or, maybe stackoverflow (https://stackoverflow.com/questions/4522431/find-duplicate-entries-in-a-column)