[mapguide-users] How to select expression with the FDO providerforSDF

[Greg Boone]

Actually, after consulting with other team members, you can achieve the
expected results using the FdoISelect command. 

 

You need to use a computed identifier; try replace the
"FdoIdentifier::Create("AREA * LAND_VALUE");" with
FdoComputedIdentifier::Create(L"AMOUNT",L"AREA * LAND_VALUE");

 

 

  FdoPtr<FdoISelect>        sampleSelect;

  FdoPtr<FdoIFeatureReader> sampleFeatureReader;

  FdoPtr<FdoIdentifier>     queryPropertyName;

 

  sampleSelect =
(FdoISelect*)m_connection->CreateCommand(FdoCommandType_Select);

  sampleSelect->SetFeatureClassName("Parcels");

 

  FdoPtr<FdoIdentifierCollection> propertyCollection =
sampleSelect->GetPropertyNames();

queryPropertyName = FdoComputedIdentifier::Create(L"AMOUNT", L"AREA *
LAND_VALUE"); 

propertyCollection->Add(queryPropertyName);

  sampleFeatureReader = sampleSelect->Execute();

  while (sampleFeatureReader->ReadNext() )

  {

      printf("(AREA * LAND_VALUE) = %ls\n",
sampleFeatureReader->GetString(L"AMOUNT") );

  }

 

 

  _____  

From: mapguide-users-bounces at lists.osgeo.org
[mailto:mapguide-users-bounces at lists.osgeo.org] On Behalf Of Greg Boone
Sent: Tuesday, February 06, 2007 10:09 AM
To: MapGuide Users Mail List
Subject: RE: [mapguide-users] How to select expression with the FDO
providerforSDF

 

I believe you need to use the FDO SelectAggregates command as generally
outlined below....

 

FdoPtr<FdoIDataReader> myDataReader;

FdoPtr<FdoISelectAggregates> selCmdAggreg;

 

selCmdAggreg = (FdoISelectAggregates*)mConnection->CreateCommand(
FdoCommandType_SelectAggregates );

selCmdAggreg->SetFeatureClassName(L"ClassA");

FdoPtr<FdoComputedIdentifier> cmpId =
(FdoComputedIdentifier*)FdoExpression::Parse(L"(PropertyA*PropertyB) AS
FunctionA");

FdoPtr<FdoIdentifierCollection> idCol =
selCmdAggreg->GetPropertyNames();

idCol->Add( cmpId );

myDataReader = selCmdAggreg->Execute();

while ( myDataReader->ReadNext() )

{

    printf("(PropertyA*PropertyB) = %ls\n",
myDataReader->GetString(L"FunctionA") );

}

 

 

-----Original Message-----
From: mapguide-users-bounces at lists.osgeo.org
[mailto:mapguide-users-bounces at lists.osgeo.org] On Behalf Of Bruno Scott
Sent: Tuesday, February 06, 2007 5:50 AM
To: mapguide-users at lists.osgeo.org
Subject: [mapguide-users] How to select expression with the FDO provider
forSDF

 

 

I'm trying to select expression using the FDO provider for SDF but it
always

return me errors

 

 

This is my sample code

 

  FdoPtr<FdoISelect>        sampleSelect;

  FdoPtr<FdoIFeatureReader> sampleFeatureReader;

  FdoPtr<FdoIdentifier> queryPropertyName;

 

  sampleSelect = (FdoISelect

*)m_connection->CreateCommand(FdoCommandType_Select);

  sampleSelect->SetFeatureClassName("Parcels");

 

  FdoPtr<FdoIdentifierCollection> propertyCollection = 

sampleSelect->GetPropertyNames();

  queryPropertyName = FdoIdentifier::Create("AREA * LAND_VALUE");

  propertyCollection->Add(queryPropertyName);

  sampleFeatureReader = sampleSelect->Execute();

 

What am i doing wrong?

 

Thanks

Bruno Scott

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