Marko Tiikkaja wrote:
> I came across this:
>
> => SELECT lead(foo) OVER(ORDER BY foo) AS foo FROM (VALUES(0)) bar(foo);
> ERROR: window functions not allowed in window definition
>
> Changing the *column alias* to something else gives the expected answer. Is
> this really the desired behaviour?
It makes sense if you refer another column:
SELECT foo*2 AS col1, lead(foo) OVER(ORDER BY col1) AS foo
FROM (VALUES(0), (1)) bar(foo);
I'm not sure what the SQL spec says about that, but it seems OK to me.
--
Heikki Linnakangas
EnterpriseDB http://www.enterprisedb.com