[postgis-users] About ESRI Shapefile ...

[Stephen Woodbridge]

Thomas Chabaud wrote:
> Sorry if it's a dumb question, but I wonder why there is no
> "AsESRIShapefileGeometry(geometry_column)" and
> "WKTFromESRIShapefile(esri_shapefile_geometry)" that could work like
> AsText() or GeometryFromText() functions.
> 
> Is it difficult to do ?
> 
> I think it could be very useful.

Hi Thomas,

1) A shapefile is not a file it is a set of files so what would you 
expect to get from "AsESRIShapefileGeometry(geometry_column)"

2) A geometry_column can contain multiple geometry type, and collection 
which are not compatible with the ESRI Shapefile spec. What would you 
want to happen in this case?

3) Lets assume we had the function as you requested it. What would you 
do with it? How would you use the result?

In general, I think that it is highly unlikely that there is any 
interest in add this function because of the compatibility, and 
restrictions, and the fact that I think you find that most people don't 
think it would be all that useful given that alternatives exist and work 
fine. But you may see a need that I don't see, and I am open to your 
ideas on how you would use such a feature.

Regarding difficulty, you might look at the source of pqsql2shp, and 
look at what it would take to wrap that in a stored procedure.

-Steve W.