[Mapserver-users] null values in postgis

Vladimir Guzmán bigfoot at main-task.com
Fri Jul 16 15:38:59 EDT 2004


I've had a simmilar problem, but with oracle, and what I did was a 
casting, for example:

data=the_geom FROM (SELECT CASE WHEN field IS NULL THEN ' ' ELSE 
CAST(field AS VARCHAR) END AS field)

And the expression would be:
EXPRESSION ([field] = ' ')

I don't know if there is a better way to do that, but it worked.

Hope that helps,

-- 
Vladimir Ilich Guzmán R.
------------------------
http://maintask.com 


Kathi Koebke wrote:

> Hello,
>
> does anybody know about problems displaying null values in mapserver ? 
> I 'm working with Postgresql/postgis and I have emtpty fields (missing 
> values) in my tables.
> I want to classify the data and I have to display missing values in my 
> map.  EXPRESSION ([ha_ges] is null) did not work .
> Any Ideas?!
> Thanks Kathi Köbke
>





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