Re: protected ON DELETE CASCADE - Mailing list pgsql-novice

From Oliver Elphick
Subject Re: protected ON DELETE CASCADE
Date
Msg-id 200108231302.f7ND1poa017052@linda.lfix.co.uk
Whole thread Raw
In response to protected ON DELETE CASCADE  (Murray Hobbs <murray@efone.com>)
List pgsql-novice
Murray Hobbs wrote:
  >
  >here's my problem
  >
  >i have tables A, B, C, D
  >
  >A <- B
  >A <- C <- D
  >
  >i want to maintain integrity so that if A is deleted from then so is
  >anything referencing from B and C - no problem ON DELETE CASCADE
  >
  >but if there are any D's that point back to A (through composite key in
  >C) i don't want the delete to go ahead - at all - i want an error
  >message and condition

If the reference from D to C uses ON DELETE RESTRICT (or NO ACTION), that
should fail and thus cause the original DELETE to fail.

--
Oliver Elphick                                Oliver.Elphick@lfix.co.uk
Isle of Wight                              http://www.lfix.co.uk/oliver
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