Question

I want to remove the last row because userid and friendwith column is duplicated.

friendshipid    userid  friendwith  friendshipstatus
183             24      102          4
151             24      52           2
155             24      66           2
179             24      66           2

thanks.

Answer 1

if you want to keep the latest friendship id then do something like this

CREATE TABLE temp_table AS (SELECT * FROM table);
DELETE FROM table WHERE friendshipid NOT IN (SELECT friendshipid FROM (SELECT * FROM temp_table ORDER BY friendshipid DESC) as temp_table GROUP BY userid, friendwith);
DROP TABLE temp_table ;

Or if you want to keep the oldest friendship id then do something like this

CREATE TABLE temp_table AS (SELECT * FROM table);
DELETE FROM table WHERE friendshipid NOT IN (SELECT friendshipid FROM (SELECT * FROM temp_table ORDER BY friendshipid ASC) as temp_table GROUP BY userid, friendwith);
DROP TABLE temp_table ;