>userId long
>picture MeduimBlob
>datePosted DateTime
>A userId can have many pictures posted. I want to write a
>query that returns a distinct userId along with the most
>recent picture posted. Can someone suggest an elegant and
>fast query to accomplish this?
Latest pic for user N:
SELECT userID,MAX(dateposted)
FROM tbl
WHERE userID=N;
Latest pics per user:
SELECT t1.userID,t1.dateposted
FROM tbl t1
LEFT JOIN tbl t2 ON t1.userID=t2.userID AND t1.dateposted<t2.dateposted
WHERE t2.userID IS NULL;
PB
