ORDER BY before SELECT?

Question

I'm just trying to add in an the newest estimated return date for a car as part of a subquery in my Select statement, I just wanted to know if this was how it is done?

I think I heard that Select happens before Order By so wanted to do a quick check.

select top 1 ESTIMATE_RETURN_DATE 
from CHECK.AOS 
where AOS.AUTO_NO = CHECK_EVENT.AUTONUM_4 
ORDER BY REVISION_NO desc

Answer 1

ORDER BY is evaluated before the SELECT, as the ordering changes the results returned.

TOP 1 also ensures the lowest REVISION_NO is returned, therefore it appears you are using the query correctly.

Answer 2

Yes Top works after OrderBY. First it will find all the records and then it would apply Top. So you are doing it right. I am also writing down the order in which a query process in sql server

FROM
WHERE
GROUP BY
HAVING
SELECT
ORDER BY
TOP/OFFSET FETCH