For these types of queries, you need to use a correlated sub-query. But as Kevin asks, what about the minimum price occuring on multiple dates?

PF

>lets say you have a stock file that has :
>stock_id, date, price and you want to find for each stock the
>minimum price and the date on which that price occurred.
>
>you can't use
>select stock_id, date, min(price)
> from stock
> group by stock_id
>
>because sql requires you to use every non aggregate field
>in the group by. any ideas?
>Oh this is in SqlServer and Postgresql
>
>Mike