Re: contains function

On Wed, Oct 05, 2005 at 01:06:37PM -0700, Frances Collier wrote:
> Are there any examples of using postgis that I can use for research?

Consider subscribing to the postgis-users mailing list if you're
using PostGIS:

http://postgis.refractions.net/support/

> Select astext(wkb_geometry), name, state
> From usroads
> Where state = 'Alabama'
> And name like '%Ross Clark%'
> And Contains(polygon('(-85.440253,31.207678),(-85.421703,31.207678),
> (-85.421703,31.226228),(-85.440253,31.226228),
> (-85.440253,31.207678)'), wkb_geometry);
>
> Here is the error I'm getting back:
>
> ERROR: function contains(polygon, geometry) does not exist
> HINT: No function matches the given name and argument types. You may need
> to add explicit type casts.

You're mixing a PostgreSQL polygon type and a PostGIS geometry type;
the Contains() function takes two geometry types. Use a constructor
like GeomFromText() or PolyFromText() to build the polygon. See
"Using PostGIS" in the PostGIS documentation for examples:

http://postgis.refractions.net/docs/

Be sure to read "Taking Advantage of Indexes" to understand how to
speed up queries such as the above with bounding box searches.

--
Michael Fuhr