Some point in the future, you’ll have to get rid of some duplicated email records in your database table. How will you do that? Well, here is a handy query for finding duplicates of any field in a table. Suppose you want to find all email addresses in a table that exist more than once, use the query below:

select email_address,
count(email_address) as NumberOccurrences
from table_user_info
group by email_address
having ( count(email_address) > 1 );

This query will give you the results below: