Aggregate Function Trouble

Problem 1:


Suppose I have a table

T( A, B, C, D, E )

I want to retrieve D, E for all rows which have minimum C when we do a group by on A and B. The query would look something like

SELECT D, E FROM T HAVING C = MIN( C ) GROUP BY A, B

Unfortunately, SQL server gives the error that D, E are not in a group by clause. One way is:

SELECT T.D, T.E
FROM
T,
(
SELECT A, B, MIN( C ) AS F FROM T GROUP BY A, B
) AS T1
WHERE
T.A = T1.A AND
T.B = T1.B AND
T.C = T1.F


What I want to know is whether there is a simpler way of doing this or not, kinda like the first illegal query.

Problem 2:

Suppose in the query

SELECT A, B, CASE WHEN C = 'A' THEN 1
WHEN C = 'B' THEN 2 END ORDER

I want to do MIN( ORDER ). The simple way would be

SELECT A, B, MIN( CASE WHEN C = 'A' THEN 1
WHEN C = 'B'' THEN 2 END )

But this gives an error. There is a way:

SELECT T.A, T.B, MIN( T.C ) FROM
(
SELECT A, B, CASE WHEN C = 'A' THEN 1
WHEN C = 'B'' THEN 2 END AS C
) AS T


but I want to know if there is a simpler way to do this (kinda like the first illegal query).

Regards,

id