[postgis] Re: postgis and shpfile library
smstnic at yahoo.ca
Fri Dec 14 18:47:19 PST 2001
I begin to work today on this function to, but not in pgsql2shp
project. I think that something like -s option for sql query in
pgsql2shp is a good idea. But to save time, I build a SQL function
with a xy min/max BOX input. This function create a view to make my
tempory spatial filter.
create view as select ... where geom && GeometryFromText('BOX3D...
Finnaly, I build a little c funtion in Postgresql that call pgsql2shp
with my tempory spatial view. The return is a simple shapefile path
for in a "www-data" or ftp directory for download.
select db2shp(mySpatialView, myDb,myshape)
It's simple and easy to build for the web... maybe this could help
--- In postgis at y..., "Obe, Regina DND\\MIS" <Regina.Obe.PFD at c...>
> I've been able to use pgsql2shp against Views too (treating views
as if they
> were tables) and seems to work pretty well. The upside of using a
> would be that if you have a query you always run you don't have to
> query results every time into a static table - it will change as
> tables change if you save the query as a view. Also it's a quick
> store the query and you can always DROP it with DROP VIEW.
> For Example instead of creating a table do something of the form
> CREATE VIEW myview As
> SELECT .... FROM ...
> Then use the myview as if it were a table in the pgsql2shp call.
> I was even able to create a view based on a UNION something of the
> CREATE VIEW myview AS
> SELECT t.Address, centroid(p.the_geom) as the_geom
> FROM table1 t INNER JOIN parcels p ON t.parcelid =
> SELECT t2.Address, centroid(the_geom) As the_geom
> FROM table2 t2 INNER JOIN parcels p ON t2.parcelid =
> Then used pgsql2shp to dump out the output with
> pgsql2shp -h myserver mydb myview
> -----Original Message-----
> From: Paul Ramsey [mailto:pramsey at r...]
> Sent: Friday, December 14, 2001 12:34 PM
> To: postgis at y...
> Subject: Re: [postgis] postgis and shpfile library
> Mapserver can also be used to write shape files as a result of a
> with the mapscript extension, but it is notoriously finnicky to get
> functionality to work write, so I would not recommend it unless you
> very patient.
> Dave Blasby wrote:
> > Jeff lounsbury wrote:
> > >
> > > Use the pgsql2shp program that comes in your postgis install.
> > > -Jeff
> > If you're just trying to get the results of a query, you can
> > table with the query results and then dump the table.
> > CREATE TABLE blah AS (SELECT ....);
> > Perhaps jeff (or someone else) could extend the pgsql2shp program
> > accept an sql query instead of a table name.
> > dave
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> | Paul Ramsey
> | Refractions Research
> | Email: pramsey at r...
> | Phone: (250) 885-0632
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