Question

I am attempting to do an UPDATE with a JOIN. I have two tables:

• player_tracking has a list of all
  players that each user has added to
  tracking.
• users is the user list. each user
  can set fsp_f to 1 or 0.

I want to update all rows in player_tracking for users who have fsp_f set to 1. Here is my example code:

   UPDATE player_tracking AS pt 
LEFT JOIN users AS u ON u.name = pt.user 
      SET pt.newtome = pt.newtome - 1 
   WHERE pt.first = 'Brett' 
     AND pt.last = 'Gardner' 
     AND pt.sport = 'mlb' 
     AND u.fsp_f = 1 

The problem is that there are 22 rows to update, yet the UPDATE query only affects 2. Why? Is my query wrong?

Here is the data found in player_tracking pertaining to “Brett” “Gardner” “mlb”:
http://pastebin.com/kyf8SCy8

Answer 1

i believe that if you change the LEFT JOIN to JOIN you will see the exact rows that get updated since you are using a field form users in the WHERE part of the statement.

so basically you are trying to check if u.fsp_f = 1 when there could be rows that do not join users and therefore will have the value as NULL.

Additionally it seems that the general layout of your query is not correct either, since you are joining on the SET statement and not in the UPDATE part – where you instructed which table to update