[MapServer-users] NULL-EXPRESSION

[angelique.kroisl at stadt-koeln.de]

Hello,
I'm trying to create a class using the class item "gst."
The attribute in the database can only have three values ​​(2000, 2100, and <NULL>).
Unfortunately, I can't create the NULL EXPRESSION.

I've already tried the following:
EXPRESSION IS NULL

EXPRESSION "<NULL>"

EXPRESSION <NULL>

EXPRESSION EMPTY

What is the correct syntax for this?

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