DB2 statement to update a header file if no corresponding record exists

Question

I have written below SQL in an RPGLE program. Intent is to update the header file (TC400F) if no corresponding records exist in detail file (TC401F). Are there better ways of doing this?

Exec SQL UPDATE  TC400F                     
            SET  T40STS = '05',             
                 T40OFL = '1'               
          WHERE  T40SID = :K#T41SID AND     
                 T40PID = :K#T41PID AND     
     NOT EXISTS  (SELECT * FROM TC401F WHERE
                 T41SID = :K#T41SID AND     
                 T41PID = :K#T41PID );      

Answer 1

Not really but you can simplify your query like this (variable are not replaced 2x)

Exec SQL UPDATE  TC400F f1                     
         SET  (f1.T40STS, f1.T40OFL) = ('05', '1')             
         WHERE  (f1.T40SID, f1.T40PID) = (:K#T41SID, :K#T41PID) AND    
         NOT EXISTS
         (SELECT * FROM TC401F f2 WHERE (f1.T40SID, f1.T40PID)=(f2.T41SID, f2.T41PID));