Question

is it possible to count fields where something?

I have following query:

SELECT * FROM 
(SELECT messages.id as id,
       messages.user_id,
       messages.category_id,
       messages.parent_id,
       messages.message,
       messages.create_date,
       messages.update_date,
       messages.status,
       users.name as username,
       users.id as userid,
       users.email as useremail,
       users.phone as userphone,
       users.active as useractive,
       users.role as userroel,
       users.date as register_date
FROM `afo_messages` as messages 
INNER JOIN `key_users` as users ON messages.user_id = users.id
WHERE messages.category_id=5 AND messages.parent_id=0
ORDER BY messages.id DESC LIMIT 30) ilv 
ORDER BY id ASC

(Here is example of output: http://lab.mirgorod.us/res.pdf)

Is it possible to add one more column to this query: Count of messages that are childs (parent_id = id of parent message)?

Answer 1

You can do it easily with sub query:

SELECT * FROM 
(SELECT messages.id as id,
       messages.user_id,
       messages.category_id,
       messages.parent_id,
       messages.message,
       messages.create_date,
       messages.update_date,
       messages.status,
       users.name as username,
       users.id as userid,
       users.email as useremail,
       users.phone as userphone,
       users.active as useractive,
       users.role as userroel,
       users.date as register_date,
       (SELECT COUNT(*) FROM afo_messages WHERE parent_id=messages.id) AS `sub messages`
FROM `afo_messages` as messages 
INNER JOIN `key_users` as users ON messages.user_id = users.id
WHERE messages.category_id=5 AND messages.parent_id=0
ORDER BY messages.id DESC LIMIT 30) ilv 
ORDER BY id ASC