Finding Duplicate Fields in a Database Table

Occasionally it is necessary to find duplicate fields within a database table.  The following query can be used to accomplish this easily.
SELECT *
FROM 'table'
WHERE ('item' IN (SELECT 'item'
FROM 'table'
GROUP BY 'item'
HAVING COUNT(*) > 1))
ORDER BY 'item'

This will list all rows in the desired ‘table’ where the given field (‘item’) is duplicated. This is a great query to use if you want to find duplicate email addresses in a database, or any other field that may be duplicated.