Jak odstranit řádek tabulky, pokud je pole post_title duplikováno v jiném řádku?

zkuste toto:

DELETE FROM Posts_Table 
WHERE Post_ID NOT IN    
    (
     SELECT a.Post_ID
     FROM
        (
         SELECT Post_Title, Post_ID 
         FROM Posts_Table 
         GROUP BY Post_Title
         ) a
    )