[postgis-users] Need some help

[David Blasby]

strk,

You might want to add constructors to postgis.  The SF SQL manual
recommends some.

Some of the obvious ones, from the user's perspective, are:

MULTIPOINT->LINESTRING
MULTILINESTRING->POLYGON
(x,y[,z]) -> POINT

you can use collect_geom(g1,g2) to build a multipoint out of single
points and multilinestrings out of linestrings.

dave

On Thu, 5 Aug 2004 19:14:31 +0200, strk <strk at keybit.net> wrote:
> On Thu, Aug 05, 2004 at 11:09:44AM -0600, Zamil Murji wrote:
> > I'm open to using pl/pgsql...any sample code to do it with that?
> 
> If you give it a try and report your code, I'm open to review it.
> Basically you'll need to construct a WKT representation of the
> line you need... see postgis manual on how to extract X/Y values
> from your points.
> --strk;
> 
> 
> 
> >
> > Thanks
> > Zamil
> >
> > -----Original Message-----
> > From: postgis-users-bounces at postgis.refractions.net
> > [mailto:postgis-users-bounces at postgis.refractions.net]On Behalf Of strk
> > Sent: Thursday, August 05, 2004 11:01 AM
> > To: PostGIS Users Discussion
> > Subject: Re: [postgis-users] Need some help
> >
> >
> > On Thu, Aug 05, 2004 at 10:53:06AM -0600, Zamil Murji wrote:
> > > Hello list,
> > >
> > > I have a column in a table defined as a LINESTRING, the lines display just fine using mapserver. Now I want to create a line that is perpendicular to that line, but I want to do it with SQL. I can get the end point of the line, but I'm at a loss of what to do next. My goal is to create a T with the line that is already stored in the db. What is the quickest way to do something like this.
> > >
> > > Thanks in advance,
> > > Zamil
> >
> > Postgis does not currently support creating geometries with SQL.
> > You need pl/pgsql for that.
> >
> > --strk;
> >
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