Select NOT IN multiple columns

Question

I need to implement the following query:

SELECT * 
FROM   friend 
WHERE  ( friend.id1, friend.id2 ) 
         NOT IN (SELECT id1, 
                        id         


        

Answer 1

I use a way that may look stupid but it works for me. I simply concat the columns I want to compare and use NOT IN:

SELECT *
FROM table1 t1
WHERE CONCAT(t1.first_name,t1.last_name) NOT IN (SELECT CONCAT(t2.first_name,t2.last_name) FROM table2 t2)