Joining to MAX date record in group

Question

Job
--------
Id
Description


JobStatus
----------
Id
JobId
StatusTypeId
Date

How do I get the current JobStatus for all jobs?

Answer 1

One way is this:

SELECT j.*, s2.StatusTypeId, s2.Date
FROM Job j
    JOIN
    (
        SELECT JobId, MAX(Date) AS LatestStatusDate
        FROM JobStatus 
        GROUP BY JobId
    ) s1 ON j.JobId = s1.JobId
    JOIN JobStatus s2 ON s1.JobId = s2.JobId AND s1.LatestStatusDate = s2.Date

Assuming you won't have 2 rows in JobStatus for the same JobId + Date combination