SQL Issue

[Fehrant]

Consider the following tables (for simplicities' sake I have used only the fields that are relevant):

 

threads (fields: threads_id)

posts (fields: posts_id, fk_threads, fk_users)

users (fields: users_id, username)

 

The issue: while posts are looped with all their respective information accordingly to which thread they belong (fk_threads -> threads_id), all the user information is also listed in each post box. Having successfully completed this, I decided to add more piece of user information, namely post count. Obviously, in order to obtain the total post count of a specific user, one would have to use COUNT on all the posts that have a matching fk_users value.

 

After trying for a while to figure out if I could make both the listing of posts with the user information, and the post count altogether in the same query, I gave up, and realized the post count would merit a separate query of its own. But even with this, I quickly came into some issues.

 

The best query I could came up with at the moment was this one:

 

SELECT users.users_id, COUNT(posts.posts_id) AS u_postcount
FROM posts
LEFT JOIN users ON posts.fk_users = users.users_id
GROUP BY users.users_id;

 

The result of this query is all the users, with all their respective post counts. However, this would be a waste of resources, as in a single thread, not every single user in the forum necessarily posted.

 

Storing the results in an array and then using an if to check if the user_id matches to show (or not) the post count was the best I could come up with at the moment.

 

Got any better ideas?

[Fehrant]

*bump*

[Fehrant]

*bump*

 

Sorry to resort to bumping like this, but I'm still having issues.

[mrdamien]

Sorry but I don't understand what the problem is. Is it not efficient enough? Did you want an INNER JOIN instead of a LEFT JOIN?

[Fehrant]

The problem is that the current query pulls up all the users, and all their corresponding post counts. Say, in this very post, the only users are you and me. So why would I bother stuffing an array with every single user post count for this post, if it's only you and me that posted? That's inefficient.

 

However, I can't seem to find the right query, or maybe I'm not facing the issue properly.

[wwelvaert]

Try using a WHERE clause instead of GROUP BY.

[Fehrant]

I thought COUNT required GROUP BY.  ???

[SirChick]

depends... if you group by it will count only the "diffent ones" rather than "all of them"

 

 

group by:

 

orange

orange

 

that equals 1

 

don't group by:

 

orange

orange

 

that equals 2

[wwelvaert]

That was a braindamaged 30-second response of mine.  You can't use WHERE but you can use HAVING, ie. something like this.

 

SELECT Count(Product_Type_Table.Price) AS CountOfPrice

FROM Product_Type_Table

HAVING (Product_Type_Table.Price=60);

[mrdamien]

If I understand correctly, you'll want a query similar to something like this:

 

SELECT users.user_id, COUNT(posts.post_id) AS u_postcount

FROM users

INNER JOIN posts ON users.user_id = posts.fk_users

INNER JOIN threads ON posts.fk_threads = threads.threads_id

WHERE threads.threads_id = ?

GROUP BY users.user_id;

 

meaning select the users and their postcount, but only the users that have posted on threads_id

[corbin]

This would require a lot of altered coding, but it would definitely be less stressful on mysql....  You could always keep a post_count column, but you would have to be careful to keep it correct between adding, deleting so on with posts.

[revraz]

You wouldn't have to bump so much if you posted this in the SQL forums instead of the PHP one.

 

*bump*

 

Sorry to resort to bumping like this, but I'm still having issues.