T-SQL Two Where Clauses on same column

Question

In SQL Server 2008, I have below Table Sample.

Name   Num
----------
John    20
John    30
Peter   10
Peter   20
Peter   30
Marry   20
Marry   30
Mike    10
Mike    20
Mike    30
Phil    10
Phil    30

I want records having Num = 10 and Num = 20. The query will return

Name   Num
----------
Peter   10
Peter   20
Mike    10
Mike    20

Many thanks.

Answer 1

You want something like this:

SELECT Name, Num
FROM tbl
WHERE Name IN (
    SELECT Name FROM tbl
    WHERE Num IN (10, 20)
    GROUP BY Name 
    HAVING COUNT(*) = 2 -- Must have all items in the set of 2
)
AND Num IN (10, 20) -- still need to restrict, since the set is not maximal

But there are other ways to skin the "set of items with all the following attributes" cat.