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

[Brent Fraser]

Yeah I saw that after I sent the message.  Take out the  <SrcSQL>, it's really 
only useful if want to do "special" things, and it can kill spatial indexing on 
ODBC datasources.  Does this work any better:

<OGRVRTDataSource>
     <OGRVRTLayer name="UserPoint">
          <SrcDataSource>ODBC:un/pw at CLO,PointData</SrcDataSource>
          <GeometryField encoding="WKB" field="Feature"/>
          <FID>PKey</FID>
     </OGRVRTLayer>
</OGRVRTDataSource>


Brent

David Lowther wrote:
> 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
>>
> 
> 
>