Top 1 with a left join

Question

Given the query below there might be multiple rows in dps_markers with the same marker key but we only want to join against the first. If I take this query and remove the t

Answer 1

Damir is correct,

Your subquery needs to ensure that dps_user.id equals um.profile_id, otherwise it will grab the top row which might, but probably not equal your id of 'u162231993'

Your query should look like this:

SELECT u.id, mbg.marker_value 
FROM dps_user u
LEFT JOIN 
    (SELECT TOP 1 m.marker_value, um.profile_id
     FROM dps_usr_markers um (NOLOCK)
         INNER JOIN dps_markers m (NOLOCK) 
             ON m.marker_id= um.marker_id AND 
                m.marker_key = 'moneyBackGuaranteeLength'
     WHERE u.id = um.profile_id
     ORDER BY m.creation_date
    ) MBG ON MBG.profile_id=u.id 
WHERE u.id = 'u162231993'