Re: quick FK question

  • From: Guillermo Alan Bort <cicciuxdba@xxxxxxxxx>
  • To: JSweetser@xxxxxxxx
  • Date: Tue, 15 Dec 2009 18:31:40 -0300

ANSI definition of FK is that the value of the column to which the
constraint applies, must be null or exists in a primary key on another
table. Oracle extends that by allowing you to reference a non-pk column. But
ANSI SQL supports null values in FK constraints (though not in the
referenced column). The solution, indeed, is to set the not null constraint
on the column.


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