Alternative to Intersect in MySQL

Question

I need to implement the following query in MySQL.

(select * from emovis_reporting where (id=3 and cut_name= \'全プロセス\' and cut_name=\'恐慌\') ) 
intersect
( sel         


        

Answer 1

AFAIR, MySQL implements INTERSECT through INNER JOIN.

Answer 2

Your query would always return an empty recordset since cut_name= '全プロセス' and cut_name='恐慌' will never evaluate to true.

In general, INTERSECT in MySQL should be emulated like this:

SELECT  *
FROM    mytable m
WHERE   EXISTS
        (
        SELECT  NULL
        FROM    othertable o
        WHERE   (o.col1 = m.col1 OR (m.col1 IS NULL AND o.col1 IS NULL))
                AND (o.col2 = m.col2 OR (m.col2 IS NULL AND o.col2 IS NULL))
                AND (o.col3 = m.col3 OR (m.col3 IS NULL AND o.col3 IS NULL))
        )

If both your tables have columns marked as NOT NULL, you can omit the IS NULL parts and rewrite the query with a slightly more efficient IN:

SELECT  *
FROM    mytable m
WHERE   (col1, col2, col3) IN
        (
        SELECT  col1, col2, col3
        FROM    othertable o
        )