Find duplicate records in MySQL

Question

I want to pull out duplicate records in a MySQL Database. This can be done with:

SELECT address, count(id) as cnt FROM list
GROUP BY address HAVING cnt >         


        

Answer 1

Why not just INNER JOIN the table with itself?

SELECT a.firstname, a.lastname, a.address
FROM list a
INNER JOIN list b ON a.address = b.address
WHERE a.id <> b.id

A DISTINCT is needed if the address could exist more than two times.