On Mon, 10 Dec 2001, Chris Albertson wrote:
> Help. I seem to have a case of "brain lock" and can't figure out
> something that I should know is simple.
>
> Here is what I am trying to do. Let's say I have a table called
> T1 with columns C1, C2, C3, C4. It contains data as follows
>
> a 1 abcd dfg
> a 2 cvfr erg
> a 3 derg hbg
> b 1 cccc rth
> c 1 rdvg egt
> c 2 derf ett
>
> I want a SQL query that returns these rows
>
> a 3 derg hbg
> b 1 cccc rth
> c 2 derf ett
>
> All I can think of is
>
> SELECT C1, max(C2), C3, C4 FROM T1 GROUP BY C1;
>
> That does not work. What I really want is the values for C1, C3
> and C4 that are associated with the row containing the maximum
> value of C2 for each group of like C1 values. I don't even need
> to know what is max(C2).
>
> Can I join the table with itself somehow? See: "brain lock".
> This should not be hard.
Maybe something like?
select t1.c1, c3, c4 from t1, (select c1, max(c2) as c2 from t1 group by
c1) foo where t1.c1=foo.c1 and t1.c2=foo.c2;