Hi all,

I would like to be able to make my postgis queries in mapserver be aware of the current draw scale. Is there an easy way to do this in the mapfile? I would like to avoid parameter substitution since mapserver is already aware of the scale, it would be nice if we could just embed a token like [scale] in a mapserver data statement and mapserver would substitute that for the current draw scale.

DATA "way from (
  select way, osm_id, landuse, name
    from osm_landuse1 where landuse is not null
     and is_large_enough(area(way),'landuse1',[scale])
  ) as foo using unique osm_id using srid=900913"

The idea here is that is_large_enough(area(way),'landuse1',[scale]) whould return true or false based on comparing area(way) to some value it looks up for 'landuse1' and the current [scale]. This would allow dynamic filtering of data in the database based on the current scale.

Likewise you could use the [scale] in a SQL case statement to dynamically change the SQL results based on scale.

It would seem that this could greatly simplify mapfiles.

-Steve W
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