Limit results with a compound, not counting the combined results?

Question

I don’t know if this is possible, I’m looking for code for writing social networks, but you need a little help.

SELECT wall.Wid, wall.uid, wall.wcomment, wall.name, comment.wid, comment.comment,comment.wid 
FROM wall 
LEFT JOIN comment ON wall.Wid=comment.wid 
WHERE wall.uid in (SELECT fid from friends where uid = 3) 

Greetings guys

Answer 1

expands as an answer:

in fact, this is not so easy to do in SQL, especially without limiting both wall posts and comments. you might be better off doing this in a loop, extracting the columns of x wall, and then for each of them, getting y comments. this way you can also cache comments for each post and save them every time.

You can limit the number of posts on the wall as follows:

SELECT wall.Wid, wall.uid, wall.wcomment, wall.name, comment.wid, comment.comment, comment.wid
FROM wall LEFT JOIN comment ON wall.Wid=comment.wid 
WHERE wall.Wid in (SELECT Wid FROM wall WHERE wall.uid IN (SELECT fid from friends where uid = 3) LIMIT 0, 10)

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Answer 2

scummy MSSQL, , somethign likethis MySQL...

SELECT
   wall.Wid,
   wall.uid,
   wall.wcomment,
   wall.name,
   comment.id,
   comment.comment,
   comment.wid
FROM
   wall
LEFT JOIN
   comment
      ON comment.id IN (SELECT id FROM comment WHERE wid = wall.wid ORDER BY id DESC LIMIT 4)
WHERE
   wall.uid IN (SELECT fid from friends where uid = 3)
   AND wall.Wid IN (SELECT Wid FROM wall ORDER BY Wid DESC LIMIT 30)

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EDIT:

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SELECT
   wall.Wid,
   wall.uid,
   wall.wcomment,
   wall.name,
   comment.id,
   comment.comment,
   comment.wid
FROM
   wall
LEFT JOIN
   comment
      ON comment.wid = wall.wid
      AND 4 >= (
               SELECT
                  COUNT(*)
               FROM
                  comment AS [newer_comment]
               WHERE
                  [newer_comment].wid = comment.wid
                  AND [newer_comment].date_added > comment.date_added
               )
WHERE
   wall.uid IN (SELECT fid from friends where uid = 3)
   AND 30 >= (
             SELECT
                COUNT(*)
             FROM
                wall AS [newer_wall]
             WHERE
                [newer_wall].uid IN (SELECT fid from friends where uid = 3)
                AND [newer_wall].date_added > wall.date_added
             )

. [date_added] [wall] [comment], , " 30"...

, , COUNT (*).

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