Question

In this example I am joining two tables.

DECLARE @AA TABLE
        (
            A1 INT,
            A2 INT
        )       
DECLARE @BB TABLE
        (
            B1 INT,
            B2 INT
        )

INSERT INTO @AA values (1,1)    
INSERT INTO @AA values (2,2)    
INSERT INTO @AA values (3,3)    

INSERT INTO @BB values (1,1)    
INSERT INTO @BB values (2,2)    
INSERT INTO @BB values (3,3)

SELECT A1, A2, B1, B2 from @AA a
        JOIN @BB b on b.B1 = a.A1
        where 1=1
        and a.A1 in (1,2)
        and b.B1 in (select max(bb.B1) from @BB bb JOIN @AA aa on bb.B1 = aa.A1 where aa.A1 in (1,2))

The above code is working since I am looking to get the result: “2,2,2,2”

Is there a more efficient way to do this? The inner select is pretty much the same as the outer select and to me it doesn’t look very nice.

Answer 1

You can just use

SELECT TOP 1 WITH TIES A1,
                       A2,
                       B1,
                       B2
FROM   @AA a
       JOIN @BB b
         ON b.B1 = a.A1
WHERE  a.A1 IN ( 1, 2 )
ORDER  BY b.B1 DESC 

Rather than running the query once to get the max(B1) then using the result of that in a filter against the same query.