Find rows that have the same value on a column in MySQL

Question

In a [member] table, some rows have the same value for the email column.

login_id | email
---------|---------------------
john     | john123@hot         


        

Answer 1

Here is query to find email's which are used for more then one login_id:

SELECT email
FROM table
GROUP BY email
HAVING count(*) > 1

You'll need second (of nested) query to get list of login_id by email.