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Re: null != null ???

From: Fran Fabrizio <ffabrizio(at)mmrd(dot)com>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: pgsql-general(at)postgresql(dot)org
Subject: Re: null != null ???
Date: 2001-10-26 16:24:51
Message-ID: 3BD98E53.FAF01D3C@mmrd.com (view raw or flat)
Thread:
Lists: pgsql-general
> Fran Fabrizio <ffabrizio(at)mmrd(dot)com> writes:
> > Can someone smarter than me tell me what I am missing?
>
> Comparisons involving NULL yield NULL.  Any book on SQL should
> explain this ...

...except 'select null=null' doesn't follow this rule (it yields 'true')
so one
can understand my confusion.  Thanks to Thomas for the explanation
and history of this interesting quirk.

-Fran



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