On Tue, 19 Nov 2002, Dan Winslow wrote:
> And given the following task :
>
> update a from b such that a.maxtype is set equal to the b.type whose val
> number is the highest for that matching id, that is, the result :
As a starting point, not using the postgresql extensions, or any thought
to make it more efficient, maybe something like:
update a set maxtype=(select type from b where b.id=a.id and
b.val=(select max(val) from b as c where c.id=b.id));
I think using postgres extensions, you could do this as:
update a set maxtype=b.type from (select distinct on (id) id, type
from b order by id, val desc) as b where a.id=b.id;
