[postgis-users] prj and SRID relation

[Gerry Creager n5jxs]

The .prj files were added when ESRI realized that the projection 
information really WAS important for shapefiles...

They're usually pretty straightforward to parse.  We should be able to 
parse them and do an SRID lookup.

gerry

strk at refractions.net wrote:
> On Thu, Oct 14, 2004 at 11:30:11AM +0800, Christopher Pedrezuela wrote:
> 
>>Greetings,
>>
>> 
>>
>>Just would like to ask if postgis supports ESRI's prj files. I noticed when
>>I exported a shp file into a postgis table, using ESRI's DI Extension, its
>>datum in the spatial reference table is "unnamed". As a result, when
>>importing from a postgis table back to a shape file, arcmap does not also
>>recognize the datum that the feature originally had. Is there a way to
>>correct this.
>>
> 
> 
> Interesting issue. I didn't know about .prj files, never met one.
> 
> For dumping we might create one, for loading it would be a little more
> tricky as the loader will have to find the corresponding SRID.
> 
> For your case (using ESRI extensions) it might be enough to change the
> SRID of you geometry table. In order to do so drop the
> enforce_srid_<geomfield> constraint, update table using setsrid on geometry
> field, re-create the enforce_srid_<geomfield> constraint.
> 
> Please let me know.
-- 
Gerry Creager -- gerry.creager at tamu.edu
Network Engineering -- AATLT, Texas A&M University	
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