SELECT * FROM OrderHeader AS Later WHERE NOT EXISTS (SELECT * FROM OrderHeader AS Earlier WHERE Earlier.ID = Later.ID AND Earlier.OrderDate < Later.OrderDate)

This will give you the earliest OrderHeader row for any matching ID value. You can then join to this as an inner query.

SELECT U.Name, OD.*, OH.*
FROM OrderDetail AS OD
INNER JOIN (SELECT * FROM OrderHeader AS Later WHERE NOT EXISTS (SELECT * FROM OrderHeader AS Earlier WHERE Earlier.ID = Later .ID AND Earlier.OrderDate < Later .OrderDate)
) AS OH ON OD.OrderID = OH.ID
INNER JOIN Users AS U ON U.ID = OH.UserID
ON U.

1. I didn’t post the SQL because you don’t have the schema to replicate, but I guess I could have just posted it. I’ll keep that in mind the next time.

2. What I mean is the earliest record of the OrderHeader with a single OrderDetail record. So the earliest order information with the detail being distinct. So in the example above, I only want a single record being returned for “Widget 1″, based on the earliest OrderDate, returning the information that is in that earliest OrderHeader Record – then joining the OrderDetail to get that detailed information.

Second, I’m not sure what you mean by “earliest record” in the detail table, since it has no DATETIME fields. How is it that you expect more than one header row for any particular detail record?

I did try to do this with a PARTITION BY clause, but the overhead is too much without putting it in a stored procedure.