[mapserver-users] expressions for Postgis layers

[Mike Leahy]

Hello list,

I'm having a bit of trouble setting up expressions for a PostGIS layer. 
  The layer is fine if I set the CLASSITEM property for the property, 
and set the EXPRESSION equal to specific values.  However, I'd like to 
be able to use more complex expressions based on one or more fields in 
the layer.  Unfortunately, I can't seem to get it to work just with a 
single field.  Below is an example of a layer in my mapfile - previously 
it was classified using the field 'lcdb1name' as the classitem.  I tried 
rewriting the expression (see below), but I just get a blank image - no 
error messages.  I'm fairly sure that I've done this before...maybe 
somebody can spot what I've missed?

Thanks for any help,
Mike

================================

LAYER
   NAME 'Land Cover Database'
   TYPE POLYGON
   CONNECTIONTYPE postgis
   CONNECTION 'host=localhost user=postgres dbname=testdb port=5432'
   DATA 'the_geom FROM lcdb_test'
   STATUS ON
   #CLASSITEM 'lcdb1name'
   CLASS
     NAME 'High Producing Exotic Grassland'
     #EXPRESSION "High Producing Exotic Grassland"
     EXPRESSION "('[lcdb1name]' = 'High Producing Exotic Grassland')"
     STYLE
       OUTLINECOLOR 192 192 192
       COLOR 170 255 0
     END
   END
END