गुम दायां कोष्ठक:अद्यतन कैस्केड पर सेट नल हटाएं (एसक्यूएल/ओरेकल) पर

Oracle में अपडेट कैस्केड पर संभव नहीं है। टॉम काइट कहते हैं:

There is not "on update cascade" automagically.

There are ways to do it, 

o deferrable constraints.  defer the foreign key check until commit, update the parent, 
update the child and then commit.

Personally -- I've never found a need or use for update cascade.  I'm opposed to it.  If 
your design requires it -- change your design now if you can.  


Primary keys are supposed to be imutable, never changing, constant.  It is an excessively 
bad practice to have to update them ever.  If there is a 0.00001% chance you will have to 
update a primary key -- then it is not a primary key, its a surrogate key and you need to 
find the true primary key (even if you have to make it up via a sequence) 

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