[Zope] NULL columns

[Jeffrey Shell]

You don't need to use the expr syntax.  If you do::

<!--#if Variable-->

the test fails on both NULL and Blank values.  Note that it also fails
on 0 (zero) since that's also an untrue expression, so there you might
want to use an expression.

NULL values are turned into "MissingValue" objects.  I can't remember
much offhand about the internals of MissingValue, but I do know that it
allows safely the ability to do most any operator on it and it won't
raise an error like the None object will.

-----Original Message-----
From: Jeff Nielsen [mailto:jeffniel@ix.netcom.com]
Sent: Wednesday, May 19, 1999 1:45 AM
To: Zope
Subject: [Zope] NULL columns


How do I test if a variable queried from a database (MS SQL Server) is
NULL
or blank?

For the blank, I can use <!--#if expr="Variable<>' '"-->, and it works
fine.
However, this test fails for NULL (It branches true when it should
branch
false...)


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