RE: Cascading Triggers

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class=115281318-09062003>Carol,
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I see
two possible issues here:
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class=115281318-09062003>1).  Is the COL-2 value changing either from/to a null value?  if so, then the WHEN clause is incorrect and the Table B trigger will not fire at all.  In other words, if COL-2's before or after value is a NULL, then the trigger will not fire.  You should make sure and include the NVL function in the WHEN clause.
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class=115281318-09062003>2).  The way I see it, if COL-2 is being updated with a non-null value, that is not equal to the old value, then the trigger will not fire.  The WHEN clause says to ONLY fire if the before and after values are the same.  It looks like it should work.
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Good
Luck!
 
Tom Mercadante <FONT face=Arial
size=2>Oracle Certified Professional

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  size=2>-----Original Message-----From: [EMAIL PROTECTED]   [mailto:[EMAIL PROTECTED]Sent: Monday, June 09, 2003 2:54   PMTo: Multiple recipients of list ORACLE-LSubject:   Cascading TriggersHi
  listers... I have a question
  related to triggers.  One of the developers here has created two triggers   as follows : Trigger #1 is an
  AFTER UPDATE trigger on TABLE-A  
       - the trigger has PL/SQL code including an UPDATE dml   statement on TABLE-B.COL-2 Trigger
  #2 is an AFTER UPDATE trigger on TABLE-B  with a WHEN clause (old.COL-1 =   new.COL-2)      
   - the trigger has  PL/SQL including an UPDATE to TABLE-C   So, here's the interesting thing...
    An update to TABLE-A fires
  Trigger #1 causing an update to TABLE-B.COL-2.   <FONT   face=sans-serif size=2>This should in turn cause Trigger #2 to fire.  But   that is not happening, or perhaps its fired, but <FONT   face=sans-serif size=2>the WHEN clause condition on TABLE-B (Trigger #2) isn't   being met for some reason. The
  question is why ?  Is there something going on with read consistancy ?    Where Trigger #2 sees the old
  (pre-updated) version of TABLE-B.COL-2 and is not aware of the new value set   by Trigger #1 ? I haven't seen much
  info on cascading triggers. Any
  thoughts or suggestions to point me in the right direction would be   appreciated. Carol
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Received on Mon Jun 09 2003 - 14:04:19 CDT