Answers for "how to avoid duplicate records in mysql"

mysql delete duplicate rows but keep one

DELETE c1 FROM contacts c1
INNER JOIN contacts c2 
WHERE
    c1.id > c2.id AND 
    c1.email = c2.email;

mysql delete duplicates

DELETE FROM CONTACTS
WHERE ID NOT IN
      (SELECT *
       FROM (SELECT max(ID)		
             FROM CONTACTS
             GROUP BY EMAIL) t);
 -- ⇓ Test it ⇓ (Fiddle source link)

how to delete all duplicate items in mysql

DELETE FROM FriendsData WHERE fID 
       NOT IN ( SELECT fID FROM FriendsData 
                   GROUP BY UserID, FriendsUserID, IsSpecial, CreatedBy)

mysql delete duplicate rows except one

DELETE FROM NAMES
 WHERE id NOT IN (SELECT * 
                    FROM (SELECT MIN(n.id)
                            FROM NAMES n
                        GROUP BY n.name) x)

delete all duplicate rows keep the latest except for one in mysql

DELETE 
FROM
  `tbl_job_title` 
WHERE id NOT IN 
  (SELECT 
    * 
  FROM
    (SELECT 
      MAX(id) 
    FROM
      `tbl_job_title` 
    GROUP BY NAME) tbl)