[gdal-dev] OGR OVF has no identified FID column

[David Lowther]

Brent,

Thanks for the reply. On initial read I thought you had found my issue -
that I was trying so many things I finally messed it all up. But on closer
inspection I am aliasing the PKey column to FID in the SrcSQL (select PKey
as FID, Feature from PointData).

When <FID>FID</FID> ogrinfo returns:

ODBC: ExecuteSQL(select PKey as FID, Feature from PointData) called.
OGR_ODBC: Table SELECT has no identified FID column.
OGR: OGROpen(test.ovf/00ED7090) succeeded as VRT.
Had to open data source read-only.
INFO: Open of `test.ovf'
      using driver `VRT' successful.
OGR: GetLayerCount() = 1

1: UserPoint
OGR: ReleaseDataSource(ODBC:un/pw at CLO/02719D10) dereferenced and now
destroying.
ODBC: SQLDisconnect()

When <FID>PKEY</FID> ogrinfo returns:

ODBC: ExecuteSQL(select PKey as FID, Feature from PointData) called.
OGR_ODBC: Table SELECT has no identified FID column.
ERROR 1: Unable to identify FID field 'PKey'.
OGR: ReleaseDataSource(ODBC:un/pw at CLO/02C39D18) dereferenced and now
destroying.
ODBC: SQLDisconnect()
FAILURE:
Unable to open datasource `test.ovf' with the following drivers.
  -> ESRI Shapefile


David Lowther
 
Coordinate Solutions, Inc.
 

-----Original Message-----
From: Brent Fraser [mailto:bfraser at geoanalytic.com] 
Sent: Thursday, August 19, 2010 3:15 PM
To: David Lowther
Cc: gdal-dev at lists.osgeo.org
Subject: Re: [gdal-dev] OGR OVF has no identified FID column

How about using:
<FID>PKey</FID>

but that doesn't explain why it takes a long time...

Best Regards,
Brent Fraser


David Lowther wrote:
> List,
> 	
> I have an OVF layer defined as follows:
> 
> <OGRVRTDataSource>
>         <OGRVRTLayer name="UserPoint">
>          <SrcDataSource>ODBC:un/pw at CLO</SrcDataSource>
>          <SrcSQL>select PKey as FID, Feature from PointData</SrcSQL>
>          <GeometryField encoding="WKB" field="Feature"/>
>   <FID>FID</FID>
>         </OGRVRTLayer>
> </OGRVRTDataSource>
> 
> The ODBC connection is to a SQL Express 2008 database. The PointData table
> is defined as follows:
> 
> CREATE TABLE [dbo].[PointData](
>  [PKey] [int] IDENTITY(1,1) NOT NULL,
>  [Feature] [geometry] NULL,
>  CONSTRAINT [PK_PointData] PRIMARY KEY CLUSTERED 
> (
>  [PKey] ASC
> )WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY =
> OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]
> ) ON [PRIMARY]
> 
> This query
> 
> select *, Feature.STAsText() from pointdata
> 
> yields
> 
> 1 0x00000000010C0000000000C062400000000000C06240 POINT (150 150)
> 
> "ogrinfo test.ovf --debug on" runs for a very long time returning many
lines
> of this sort of stuff:
> 
> ERROR 4: Update access not supported for VRT datasources.
> OGR_ODBC: EstablishSession(DSN:"CLO", userid:"un", password:"pw")
> ODBC: SQLConnect(CLO)
> ODBC: CatalogNameL: (null)
> Schema name: (null)
> 
> OGR_ODBC: Table PointData has no identified FID column.
> OGR_ODBC: Table UserMapData has no identified FID column.
> OGR_ODBC: Table CHECK_CONSTRAINTS has no identified FID column.
> 
> before finally saying:
> 
> OGR: OGROpen(ODBC:un/pw at CLO/02C79D10) succeeded as ODBC.
> ODBC: ExecuteSQL(select PKey as FID, Feature from PointData) called.
> OGR_ODBC: Table SELECT has no identified FID column.
> OGR: OGROpen(test.ovf/00E17090) succeeded as VRT.
> Had to open data source read-only.
> INFO: Open of `test.ovf'
>       using driver `VRT' successful.
> OGR: GetLayerCount() = 1
> 
> 1: UserPoint
> OGR: ReleaseDataSource(ODBC:un/pw at CLO/02C79D10) dereferenced and now
> destroying.
> ODBC: SQLDisconnect()
> 
> GDAL version is 1.6.0.
> 
> I have tried using no FID tag and using SrcLayer instead of SrcSQL.
Anybody
> know what I could do to make it see the FID? I'm guessing it would be a
lot
> faster if it didn't check every table in the database for an FID...
> 
> Thanks in advance for your assistance,
> 
> Dave Lowther
>