Gathering data from two tables

[OutOfInk]

I have two tables that relate to each other;

 

tableA has a Columns ID, NAME, BETRESULT

 

tableB has all the users register data;

 

Each user places a bet on a sport for the week and they either win or lose there credits.  What i wish to do is take away 20 credits from users that dont place a bet for the week.

 

So anyone that does bet i INSERT a new row into tableA. I need to some how work out what usernames havent bet in tableA and remove 20 credits from tableB; I wrote this query but it ended up taking 20 credits off every user.

 

SELECT bets.name, Register.SNAME FROM bets INNER JOIN Register ON bets.name = Register.SNAME

 

 

If someone could help thanks in advance!

 

[ninedoors]

Try something like this:

SELECT bets.name, Register.SNAME 
FROM Register 
LEFT JOIN bets ON bets.name = Register.SNAME 
WHERE bets.name IS NULL

You will need a timestamp column in your bets table if you want to restrict it to a time frame.