[Mapserver-users] MORE PostGIS Questions - Expression

Zamil Murji Zamil.Murji at divestco.com
Tue Jul 8 18:34:17 EDT 2003


Thank you once again,

The list comes through in a big way. Using a classitem works great. Here is my layer definition:
#PostGIS Data Layer
LAYER
   NAME "oilwells-selected"
   TYPE point
   STATUS off
   CONNECTIONTYPE postgis
   CONNECTION "user=idc dbname=idc host=sdb2 port=5432" 
#   DATA "geom from (select * from oilwells) as foo using unique id using SRID=4326" 
   DATA "geom from oilwells"
   CLASSITEM well_id
   CLASS
     EXPRESSION /x/
     COLOR 0 255 0
     SYMBOL 'circle'
     SIZE 20
#     TEMPLATE "c:\\mapfiles\test.html"
   END
END

-----Original Message-----
From: Paul Ramsey [mailto:pramsey at refractions.net]
Sent: Tuesday, July 08, 2003 3:56 PM
To: mapserver-users at lists.gis.umn.edu
Subject: Re: [Mapserver-users] MORE PostGIS Questions - Expression


Your EXPRESSION does not reference a column name. That is only "OK" as long as 
you define a CLASSITEM in the LAYER, for the CLASSes to refer to. I don't know 
if regex expressions work in the context of the CLASSITEM, though. It might 
only be direct equality tests.

MAP
  ...
  LAYER
    CLASSITEM foo
    ...
    CLASS
      EXPRESSION bar
      ...
    END
  END
END

Quoting Zamil Murji <Zamil.Murji at divestco.com>:

> Hello all,
> 
> I am using the cgi version of mapserv. With shapefiles it is possible to
> dynamically select items in a layer by passing them along the url and using
> the corresponding EXPRESSION tag in the .map file. I want to do something
> similar with PostGIS, can this be done?
> 
> Here are 3 rows from my db and my .map file for them:
> idc=# select * from oilwells;
>  well_id |                 geom                 | name
> ---------+--------------------------------------+-------
>        1 | SRID=4326;POINT(-110.04146 49.01449) | ONE
>        2 | SRID=4326;POINT(-110.24459 49.01449) | TWO
>        3 | SRID=4326;POINT(-110.43138 49.01449) | THREE
> (3 rows)
> 
> #PostGIS Data Layer
> LAYER
>    NAME "oilwells"
>    TYPE point
>    STATUS off
>    CONNECTIONTYPE postgis
>    CONNECTION "user=idc dbname=idc host=sdb2 port=5432"
> #   DATA "geom from (select * from oilwells) as foo using unique id using
> SRID=4326"
>    DATA "geom from oilwells"
>    CLASS
> #     EXPRESSION /x/
>      COLOR 0 0 0
>      SYMBOL 'circle'
>      SIZE 20
> #     TEMPLATE "c:\\mapfiles\test.html"
>    END
> END
> 
> If I take uncomment EXPRESSION tag, then this layer never shows up. Please
> help
> 
> Thanks
> Zamil
> 
> _______________________________________________
> Mapserver-users mailing list
> Mapserver-users at lists.gis.umn.edu
> http://lists.gis.umn.edu/mailman/listinfo/mapserver-users
> 



_______________________________________________
Mapserver-users mailing list
Mapserver-users at lists.gis.umn.edu
http://lists.gis.umn.edu/mailman/listinfo/mapserver-users




More information about the mapserver-users mailing list