how to delete duplicates in mysql code example
Example 1: 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 2: mysql remove duplicates
DELETE FROM table_name WHERE id
NOT IN ( SELECT id FROM table_name
GROUP BY field_1, field_2)
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 delete older duplicates
delete test
from test
inner join (
select max(id) as lastId, email
from test
group by email
having count(*) > 1) duplic on duplic.email = test.email
where test.id < duplic.lastId;