Select and display only duplicate records in mysql

Question

This question is pretty simple I for some reason cant get the proper result to display only the duplicate records

Table   : Paypal_ipn_orders
id                      


        

Answer 1

This works the fastest for me

SELECT
    primary_key
FROM
    table_name
WHERE
    primary_key NOT IN (
        SELECT
            primary_key
        FROM
            table_name
        GROUP BY
            column_name
        HAVING
            COUNT(*) = 1
    );