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GC2-Vidi-workshop
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Where can I read more about expressions? #1

Open velle opened 1 year ago

velle commented 1 year ago

On this page: https://mapcentia.github.io/GC2-Vidi-workshop/05-setup-mapserver/

Expression: Each object in the layer is evaluated against Expression. If the result is true, its assigned the object class. If the layer only has one class, Expression is not necessary. Without Expression the class will be assigned to all the objects in the layer. Read more about expressions.

But where can I read more about expressions? Is there a link missing?

And also, does it work like the filters in Vidi? Should I be able to copy a filter from vidi and paste it into the expression field here? I was expecting so, but I have not had luck with any expression that references an attribute.

Sincerely

mapcentia commented 1 year ago

Expressions are MapServer expressions: https://mapserver.org/mapfile/expressions.html

An example of an expression:

"[fieldname]" = "value"

The [ ] should be typed out as shown.

Vidi is using SQL where clauses.