3 sql inner joined tables, now how to count total rows in them

Question

here is the query, I have inner joined 3 tables, Now i am looking to count all rows in the result i.e. 78 by executing query on php my admin, I don't want result of table, i jst want 1 row in wchich only thing written is 78, same as we do in

SELECT count (*) FROM test_table

Below is the query of 3 inner joined tables

        SELECT 
mybb_users.uid,
mybb_users.username,
mybb_users.avatar,
mybb_posts.fid,
mybb_posts.uid,
mybb_posts.dateline,
mybb_posts.tid,
mybb_posts.subject,
mybb_forums.parentlist,
mybb_forums.fid
FROM mybb_forums
    INNER JOIN mybb_posts ON mybb_forums.fid = mybb_posts.fid
    INNER JOIN mybb_users ON mybb_posts.uid = mybb_users.uid
    WHERE mybb_forums.parentlist LIKE '%58%'
    GROUP BY mybb_posts.tid
    ORDER BY mybb_posts.dateline DESC

now how to count total number of rows in it ?

EDITED

 SELECT count( mybb_users.uid ) AS totalOfRows
FROM (

SELECT mybb_users.uid, mybb_users.username, mybb_users.avatar, mybb_posts.fid, mybb_posts.uid AS uidPost, mybb_posts.dateline, mybb_posts.tid, mybb_posts.subject, mybb_forums.parentlist, mybb_forums.fid AS fidForum
FROM mybb_forums
INNER JOIN mybb_posts ON mybb_forums.fid = mybb_posts.fid
INNER JOIN mybb_users ON mybb_posts.uid = mybb_users.uid
WHERE mybb_forums.parentlist LIKE '%58%'
GROUP BY mybb_posts.tid
)T

Error ::#1054 - Unknown column 'mybb_users.uid' in 'field list'

Answer 1

well, if you don't want the result, why are you showing those fields ? A select return one table, so apply count to it:

SELECT 
count(*)
FROM mybb_forums
    INNER JOIN mybb_posts ON mybb_forums.fid = mybb_posts.fid
    INNER JOIN mybb_users ON mybb_posts.uid = mybb_users.uid
    WHERE mybb_forums.parentlist LIKE '%58%'
    GROUP BY mybb_posts.tid

Also, you're groupying by posts, so, don't need to order

Edit: I think the query I've posted should work, anyway, if it's not, this definitely should work:

SELECT sum(Total) AS totalOfRows 
FROM ( 

SELECT 1 as Total 
FROM mybb_forums 
INNER JOIN mybb_posts ON mybb_forums.fid = mybb_posts.fid 
INNER JOIN mybb_users ON mybb_posts.uid = mybb_users.uid 
WHERE mybb_forums.parentlist LIKE '%58%' 
GROUP BY mybb_posts.tid 
)T