Question

My question is kinda simple… Let’s suppose I have two simples tables on a 1-N relationship:

Order
----------
Id

Order_Status
--------------
Id
OrderId
Description
DateTimeStatus

I need to retrieve the following result: OrderId and the most recent Status’s Description and Timestamp.

Usually I do things like this:

SELECT
    o.Id,
    st.Description,
    st.DateTimeStatus
FROM Order o
JOIN OrderStatus st ON
    st.OrderId = o.id
    AND
    st.DateTimeStatus = (
        SELECT MAX(st1.DateTimeStatus)
        FROM OrderStatus st1
        WHERE st1.OrderId = o.Id
    )

But I don’t think it’s the prettiest way, nor the most performatic one, thinking on more huge queries (and it’s not safe without limiting the subquery result).

I could also simply join the two tables, ordering in descencing way the st.DateTimeStatus and limiting the result to 1.

Well.. Any better approach?

I researched for similar questions but haven’t found something similar to what I want to know: the best approaches.

Answer 1

I could also simply join the two tables, ordering in descencing way the st.DateTimeStatus and limiting the result to 1.

I think you would be hard-pressed to find a more performant option than this.