mysql remove duplicate values in column code example
Example 1: mysql remove duplicates
DELETE FROM table_name WHERE id
NOT IN ( SELECT id FROM table_name
GROUP BY field_1, field_2)
Example 2: 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;
Example 3: 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)
Example 4: mysql remove duplicates
DELETE t1 FROM contacts t1
INNER JOIN contacts t2
WHERE
t1.id < t2.id AND
t1.email = t2.email;Code language: SQL (Structured Query Language) (sql)