How do I put an 'if clause' in an SQL string?

Question

So here\'s what I want to do on my MySQL database.

I would like to do:

SELECT *
    FROM itemsOrdered
    WHERE purchaseOrder_ID = \'@purchaseOr         


        

Answer 1

Select FROM t1
    WHERE s11 > ANY
        (SELECT col1,col2 FROM t2
            WHERE NOT EXISTS
                (SELECT * FROM t3
                    WHERE ROW(5*t2.s1,77)=
                        (SELECT 50,11*s1 FROM t4 UNION SELECT 50,77 FROM
                            (SELECT * FROM t5) AS t5)));