SQL for Returned Seats

Hey all,

I have to make some fundraising lists and I knew that a simple pull from Ticket History would exclude anybody that has returned a ticket but how do I find those people? I wrote a simple query that looks at the transaction table to find transactions with a value of LESS than 0. You just need to put your own perf numbers in after the WHERE perf_no IN clause. 

SELECT DISTINCT b.customer_no
FROM T_TRANSACTION a
INNER JOIN T_ORDER b ON a.order_no = b.order_no
WHERE perf_no IN ('823','824','825','826','827','828','829','830','743','744','746','747','745') and trn_amt < 0;

You can easily paste this into list manager to find anybody with a returned ticket. You could expand on this by joining a table with the prod season table so you don't have to type out those performance numbers but in our case it wasn't that many performances really.