Defining a line from SQL server using OGR

[Frank Warmerdam]

Chip Taylor wrote:
> I am retrieving a set of point from SQL Server using OGR.  If I declare 
> the layer type to be "Point" then it works fine.  However, I want the 
> series of XY coordinates to define a line.  If I declare the layer type 
> "Line" nothing renders.  Any help would be appreciated.  Here is the 
> layer code defined as a line (there are two xy points in the database):
...
> 
>  '<OGRVRTDataSource>
>        <OGRVRTLayer name="GPSData">
>         <SrcDataSource>ODBC:myUser/myPwd at myDSN</SrcDataSource>
>        <SrcSQL>EXEC pGetTracking</SrcSQL>
>        <GeometryType>wkbLineString</GeometryType>
>         <GeometryField encoding="PointFromColumns" x="gpsLongitude" 
> y="gpsLatitude"/>
>       </OGRVRTLayer>
>   </OGRVRTDataSource>'

Chip,

what are the types of your gpsLongitude columns?  Are they array types
of some kind?  Or perhaps you are hoping that OGR will collect all the
rows, and make it into a single linestring features?

Basically, this is not supported.  If you could do something in the
database to prepare an appropriate line geometry in WKT format, you
could use the WKT column support in VRT.

Best regards,
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