mysql - Using SQL joins to determine order of a post -


i trying fetch forum topics based on amount of replies has been submitted topic. new understanding how sql joins work, though have been using sql awhile in general, though feel on right track. have query:

select * `topics` inner join (     select count(tid) countedreplies,`tid`     `replies`     group `tid` ) on topics.id = replies.tid order replies.countedreplies desc

table structures this:

topics

id        topic name 1         filler topic name 2         exciting posts excellence 3         random name example

replies

id       tid       post 1        3         hooray! wonderful! 2        3         post topic id 3 well! 3        1         topic 1 better topic 1.

my expected result

i getting nothing in return, though trying this:

1. random name example 2. filler topic name 3. exciting posts excellence

you can use left join without involving sub select

select t.* `topics` t left join `replies` r on t.id = r.tid group t.id order count(r.tid) desc

demo


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