Question

I have a MySQL query that is baffling me. I am trying to grab specific pieces of information from two different tables (blurbs and users), while restricting it to only people who are following.

I have the following query:

SELECT DISTINCT blurbs.text, blurbs.timestamp, users.name, 
     users.username, users.profilepic, users.id 
FROM blurbs,users 
LEFT OUTER JOIN follows 
ON blurbs.uid = follows.following AND follows.follower = ? 
WHERE (blurbs.uid = $user_id OR follows.following IS NOT NULL) 
     AND (LOWER(blurbs.text) LIKE '%$query%' OR LOWER(users.name) LIKE '%$query%') 
     AND blurbs.is_private=0 AND blurbs.uid=users.id 
LIMIT 0,30

It’s not working properly, but I am getting overly confused because of the joins.

What should I do to remedy this?

Answer 1

Try using all the join condition through where clause only e.g.

      select a.*, b.*     //<-- Selectign data from first two tables
      from table1 a, table2 b, table1 c
       where a.id = b.id         //<-- joining condition for first two tables
       and a.xxx= c.yyyyy        //some relation with third table
       and c.aaa =....           //filter conditions using third table
       and c.bbb =...            //filter conditions using third table

Trying to rephrase your query as below:

   SELECT DISTINCT blurbs.text, blurbs.timestamp, users.name, 
       users.username, users.profilepic, users.id 
   FROM blurbs,users, follows
   WHERE blurbs.uid=users.id
     AND blurbs.uid = follows.following 
     AND follows.follower = ?
     AND (blurbs.uid = $user_id OR follows.following IS NOT NULL) 
     AND (LOWER(blurbs.text) LIKE '%$query%' OR LOWER(users.name) LIKE '%$query%') 
     AND blurbs.is_private=0
   LIMIT 0,30

Having done this, I hope you can better control/manage the desired filter conditions.