Restrict number of listings in SQL - sql

Question

We have a top ten video list that is displayed on our dashboard. Sometimes we have a situation where one user has posted 6 videos and all of them have made it into the top ten (Most Views). My boss only wants to display the top 2 from any one member in the top ten.
How does one do that. Here is the script I am using to extract the data:
SELECT a.MediaID,
COUNT(a.MediaID) AS TimesViewed
FROM MediaViewLog a
INNER JOIN MemberVideo b ON b.MemberVideoID = a.MediaID
INNER JOIN Member c ON c.MemberID = b.MemberID
WHERE a.ViewDate BETWEEN '5/25/2013 10:04:23 AM' AND '12/12/2050 11:59:59 PM'
AND a.MediaType = 'V'
AND b.CreateDate > '5/25/2013 10:04:23 AM'
AND c.SBIcon = 'N'
GROUP BY a.MediaID
MediaViewLog contains the following data:
+----------------+---------+-----------+-------------------------+
| MediaViewLogID | MediaID | MediaType | ViewDate |
+----------------+---------+-----------+-------------------------+
| 3336 | 7033 | V | 2013-05-26 03:36:52.573 |
+----------------+---------+-----------+-------------------------+
| 3337 | 7037 | V | 2013-05-26 04:22:16.682 |
+----------------+---------+-----------+-------------------------+
| 3338 | 12356 | A | 2013-05-26 03:36:52.573 |
+----------------+---------+-----------+-------------------------+
| 3339 | 7102 | V | 2013-05-26 07:12:25.428 |
+----------------+---------+-----------+-------------------------+
| 3340 | 7058 | V | 2013-05-26 08:02:27.003 |
+----------------+---------+-----------+-------------------------+
| 3341 | 7033 | B | 2013-05-26 03:36:52.573 |
+----------------+---------+-----------+-------------------------+
Each Media is associated with a Member, in the "Member" Table. "MemberID" is the Primary Key
Any ideas how I can only extract the top 2 if there is more than one for any member, as part of the top 10.
Any help would greatly appreciated.
Thanks!

Answer 1

For this, use the row_number() function:
select t.MediaId, t.TimesViewed
from (SELECT a.MediaID, c.MemberId, COUNT(a.MediaID) AS TimesViewed,
row_number() over (partition by c.MemberId order by count(a.MediaId) desc
) as seqnum
FROM MediaViewLog a
INNER JOIN MemberVideo b ON b.MemberVideoID = a.MediaID
INNER JOIN Member c ON c.MemberID = b.MemberID
WHERE a.ViewDate BETWEEN '5/25/2013 10:04:23 AM' AND '12/12/2050 11:59:59 PM'
AND a.MediaType = 'V'
AND b.CreateDate > '5/25/2013 10:04:23 AM'
AND c.SBIcon = 'N'
GROUP BY a.MediaID, c.MemberId
) t
where seqnum <= 2;
This is assuming that each video is posted by only one member. That is, that grouping by MediaId and by a.MediaId, c.MemberId is really the same thing. Otherwise, you are mixing counts from different users (on the "posting" side of the video, not the viewing), and extracting only two for each user is much harder.
I also think there should be a top 10 in there somewhere.