[postgis-users] postgis and mapserver - queries

David Blasby dblasby at refractions.net
Mon Jun 9 10:24:32 PDT 2003

C F wrote:
> What does mappostgis.c do (I don't see it in my PostGIS source)?  I'm 
> curious, because I'm doing some similar operations using the EXPLAIN 
> VERBOSE method.  Without writing a full blown SQL parser, I don't see a 
> better way.  It seems like the best way would be to hook into the 
> actualy SQL parser being used by Postgres... but maybe that's too 
> difficult and that could change as well.

mappostgis.c is part of Mapserver.  Part of its functionality is to 
'query' for a layer.  Functionally it looks like this:

a. ask the layer for its columns
b. ask the layer to give you a feature with a specific id

It was orginally designed for Shapefiles, so this order makes sense (the 
columns are known apriori).  Unfortunately, for DB connections, this is 


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