Re: comparing rows

At 10:23 AM 8/3/00 -0400, Tom Lane wrote:
>Don Baccus <dhogaza@pacifier.com> writes:
>> If foo = NULL is illegal, doesn't this make it rather difficult to
>> say things like table1.i = table2.i for tables that contain NULLs
>> in column i?
>
>Thomas is not saying that the *operation* is illegal.  His point is
>purely a syntactic one: SQL92 allows the keyword "NULL" only in certain
>specified contexts, and out on its own as a component of an arithmetic
>expression ain't one of them. 

I misunderstood, didn't check for the use of the literal, just the
semantics of the operations.

>As far as I can see, allowing NULL as a general-purpose literal is a
>perfectly reasonable spec extension that *everybody* does, including us.
>Thomas may be the only person anywhere who is bothered by it ;-)

Thomas, do you have a reference into the standard?



- Don Baccus, Portland OR <dhogaza@pacifier.com> Nature photos, on-line guides, Pacific Northwest Rare Bird Alert
Serviceand other goodies at http://donb.photo.net.