Find ids that are NOT in other two tables.

[Yesmin Patwary]

Dear All,
   
  Need to find ids that are NOT in other two tables.  With the help of PHP 
scripting and three queries I am able to do the task.  Can this be done with 
one mysql query? 
   
  Below are current quires: 
   
  SELECT DISTINCT company_id  FROM company_db
SELECT company_id  FROM person WHERE company_id=\"$company_id\"
SELECT company_id FROM customer WHERE company_id=\"$company_id\"
   
  Thanks in advance for any help.

                
---------------------------------
How low will we go? Check out Yahoo! Messenger’s low  PC-to-Phone call rates.