HELP:How to create the trigger?

From: Violin <violin.hsiao_at_mail.pouchen.com.tw>
Date: Wed, 16 Sep 1998 01:36:15 GMT
Message-ID: <36051609.6078951@news.twsc.pouchen.com.tw>

Hello,
I have a BIG....BIG problem,and I hope someone could help me!!! I have a tables:VOUFD
I want to create a trigger:BEFORE DELETE ON VOUFD FOR EACH ROW

VOUFD                              Primmary Key    
----------------------------------------------------------   
vou_no       CHAR(8)               \/
ord_no       CHAR(8) 
qty               NUMBER

If I delete a row from VOUFD,
I want to check if there is any other row where ord_no = :old.ord_no So I have the script like this:

CREATE OR REPLACE TRIGGER DEL_VOUFD

       BEFORE DELETE 
       ON VOUFD
       FOR EACH ROW
DECLARE
       temp  CHAR(8);
       CURSOR C1 IS
                 SELECT VOU_NO FROM VOUFD WHERE ORD_NO = :old.ord_no;

BEGIN
     temp := '';
     OPEN C1;
     FETCH C1 INTO temp;
     IF C1%FOUND THEN
        temp := '1';
     ELSE 
        temp := '2';
     END IF;
     ::::::::::::::::::::::::::::

END DEL_VOUFD; And the trigger is created successfully. But when I do "delete" command:
DELETE FROM VOUFD WHERE VOU_NO = '000001'; An error occurs:
ORA-04091: table SCOTT.VOUFD is mutating,

                         trigger/function may not see it
ORA-06512: at "SCOTT.DEL_VOUFD", line 4

ORA-06512: at "SCOTT.DEL_VOUFD", line 7 ORA-04088: error during execution of trigger 'SCOTT.DEL_VOUFD'

SOS:How could I sove the problem??Could anyone help me? Please give me some suggestions.
and please Cc to : violin.hsiao_at_mail.pouchen.com.tw Best Regards. :-)

Violin. Received on Tue Sep 15 1998 - 20:36:15 CDT