In a [member] table, some rows have the same value for the email column.
login_id | email
---------|---------------------
john | john123@hotmail.com
peter | peter456@gmail.com
johnny | john123@hotmail.com
...
Some people used a different login_id but the same email address, no unique constraint was set on this column. Now I need to find these rows and see if they should be removed.
What SQL statement should I use to find these rows? (MySQL 5)