BUG: Oledb32.dll Truncates Data at the Embedded Null-termination Character if a Column Is Bound to DBTYPE_WSTR (313925)

MORE INFORMATION

Steps to Reproduce Behavior

Bind a varchar column that has a hexadecimal value of 0x4142430044 in the database table to a DBTYPE_WSTR data type in the application. To do this, follow these steps:

1. In a SQL server database named PUBS, create a table with a varchar column, as follows:

   CREATE TABLE myTest (col1 varchar (20) NOT NULL)
   					

2. Insert a record into this table with 0x00 embedded in the data, as follows:

    INSERT INTO testVarchar VALUES (0x4142430044)
   					

3. In Microsoft Visual C++ version 6.0, create a new Console Application project that contains the following code:

   #define UNICODE
   #define _UNICODE
   #define DBINITCONSTANTS
   #define INITGUID
   #define MAX_LEN 100
   
   #include <windows.h>
   #include <stdio.h>
   #include <oledb.h>
   #include <oledberr.h>
   
   void main()
   {
   IDBInitialize * pIDBInitialize = NULL;
   IDBProperties * pIDBProperties = NULL;
   ICommandText *		pICommandText;
   IRowset *			pIRowset;
   IAccessor *			pIAccessor;
   IDBCreateSession * pIDBCreateSession;
   IDBCreateCommand * pIDBCreateCommand;
   CLSID clsid;
   const ULONG nProps = 1;
   DBPROP InitProperties[ nProps ];
   DBPROPSET rgInitPropSet;
   HRESULT				hr;
   BYTE*				pRowValues;
   HACCESSOR			hAccessor;
   LONG				cRowsAffected;
   DBBINDING *			pDBBindings = NULL;
   ULONG cbRow = 0;
   ULONG cRowsObtained;
   LPOLESTR bSQLString = OLESTR( "select col1 from pubs..myTest" );
   HROW rghRows[ 1 ];
   HROW * pRows = & rghRows[ 0 ];
   ULONG iRow;
   
   	VariantInit( &InitProperties[ 0 ].vValue );
   	InitProperties[ 0 ].dwOptions = DBPROPOPTIONS_REQUIRED;
   	InitProperties[ 0 ].colid = DB_NULLID;
   	InitProperties[ 0 ].dwPropertyID = DBPROP_INIT_PROVIDERSTRING;
   	InitProperties[ 0 ].vValue.vt = VT_BSTR;
   	InitProperties[ 0 ].vValue.bstrVal = 
   	Server=kavi1;database=pubs;uid=sa;pwd=sa;
    
   	rgInitPropSet.guidPropertySet = DBPROPSET_DBINIT;
   	rgInitPropSet.cProperties = nProps;
   	rgInitPropSet.rgProperties = InitProperties;
   
   	CoInitialize( NULL );
   
   	CLSIDFromProgID( L"SQLOLEDB", & clsid );
   
   	hr = CoCreateInstance( clsid, 
   				NULL, 
   				CLSCTX_INPROC_SERVER, 
   				IID_IDBInitialize, 
   				( void ** ) & pIDBInitialize );
   
   	if( pIDBInitialize == NULL )
   	{
   		printf( "CoCreateInstance failed.\n" );
   		return;
   	}
   
   	pIDBInitialize->QueryInterface( IID_IDBProperties,
   		( void ** ) & pIDBProperties );
   
   	hr = pIDBProperties->SetProperties( 1, & rgInitPropSet );
   
   	SysFreeString( InitProperties[ 0 ].vValue.bstrVal );
   
   	pIDBProperties->Release();
   
   	if( FAILED( hr ) )
   	{
   		printf( "Set properties failed.\n" );
   		return;
   	}
   
   	if( FAILED( hr = pIDBInitialize->Initialize() ) )
   	{
   		printf( "Initialize) failed\n" );
   	}
   
   	// Get the db session object
   	if( FAILED( pIDBInitialize->QueryInterface( IID_IDBCreateSession,
   		( void ** ) & pIDBCreateSession ) ) )
   	{
   		printf( "Session Initialization failed.\n" );
   		return;
   	}
   
   	// create the session
   	if( FAILED( pIDBCreateSession->CreateSession( NULL,
   		IID_IDBCreateCommand,
   		( IUnknown ** ) & pIDBCreateCommand ) ) )
   	{
   		printf( "Create session failed.\n" );
   		pIDBCreateSession->Release();
   		return;
   	}
   
   
   	// Create the command object
   	if( FAILED( pIDBCreateCommand->CreateCommand( NULL,
   		IID_ICommandText,
   		( IUnknown ** ) & pICommandText ) ) )
   	{
   		printf( "Create command failed.\n" );
   		return;
   	}
   
   	pIDBCreateCommand->Release();
   
   	// provide the command, language and dialect
   	if( FAILED( pICommandText->SetCommandText( DBGUID_DBSQL, bSQLString ) ) )
   	{
   		printf( "Could not set CommandText\n" );
   		return;
   	}
   
   	if( FAILED( hr = pICommandText->Execute( NULL, 
   		IID_IRowset, 
   		NULL, 
   		& cRowsAffected, 
   		( IUnknown ** ) & pIRowset ) ) )
   	{
   		printf( "Execute failed\n" );
   		return;
   	}
   
   	pDBBindings = new DBBINDING[1];
   
   		pDBBindings[ 0 ].iOrdinal = 1;
   		pDBBindings[ 0 ].obValue = 8;
   		pDBBindings[ 0 ].obLength = 4;
   		pDBBindings[ 0 ].obStatus = 0;
   		pDBBindings[ 0 ].pTypeInfo = NULL;
   		pDBBindings[ 0 ].pObject = NULL;
   		pDBBindings[ 0 ].pBindExt = NULL;
   		pDBBindings[ 0 ].dwPart = DBPART_VALUE | DBPART_STATUS | DBPART_LENGTH;
   		pDBBindings[ 0 ].dwMemOwner = DBMEMOWNER_CLIENTOWNED;
   		pDBBindings[ 0 ].eParamIO = DBPARAMIO_NOTPARAM;
   		pDBBindings[ 0 ].cbMaxLen = MAX_LEN;
   		pDBBindings[ 0 ].dwFlags = 0;
   		pDBBindings[ 0 ].wType = DBTYPE_WSTR;
   		pDBBindings[ 0 ].bPrecision = 0;
   		pDBBindings[ 0 ].bScale = 0;
   
   	pRowValues = new BYTE[ MAX_LEN ];
   	memset( pRowValues, 0, MAX_LEN );
   
   	// create an accessor to fetch the data with
   	hr = pIRowset->QueryInterface( IID_IAccessor, ( void ** ) & pIAccessor);
   
   	if( FAILED( hr ) )
   	{
   		printf( "QI for IAccessor failed\n" );
   		return;
   	}
   
   	if( FAILED( hr = pIAccessor->CreateAccessor( DBACCESSOR_ROWDATA, 
   			1, 
   			pDBBindings, 
   			sizeof( pDBBindings ),
   			& hAccessor,
   			NULL ) ) )
   	{
   		printf( "CreateAccessor() failed\n" );
   		return;
   	}
   
   
   	// process the rows 
   	while( TRUE )
   	{
   		hr = pIRowset->GetNextRows( 0, 0, 10, & cRowsObtained, & pRows );
   
   		// all done, there are no more rows to get
   		if( cRowsObtained == 0 )
   			break;
   
   		// loop over rows obtained, getting data for each
   		for( iRow = 0 ; iRow < cRowsObtained ; iRow++ )
   		{
   			hr = pIRowset->GetData( rghRows[ iRow ], hAccessor, pRowValues );
   			printf("Length of row[%d]:%d\n",iRow+1,*(pRowValues+4));
   			printf("Value of Col1:");
   	
   			for(int byteCnt=0;byteCnt<(*(pRowValues+4))-1;byteCnt++)
   						printf( "%x",(pRowValues+8)[byteCnt]);
   			
   			printf("\n\n");
   		}
   		pIRowset->ReleaseRows( cRowsObtained, rghRows, NULL, NULL, NULL );
   	}
   	pIAccessor->ReleaseAccessor( hAccessor, NULL );
   	pIAccessor->Release();
   	pIRowset->Release();
   	pICommandText->Release();
   	pIDBCreateSession->Release();
   
   	delete [] pDBBindings;
   	delete [] pRowValues;
   	
   	if( pIDBInitialize )
   		if( ! FAILED( hr=pIDBInitialize->Uninitialize() ) )
   			pIDBInitialize->Release();
   		else
   			printf( "Uninitialize failed.\n Something didn't get released.\n" );
   }
   					

4. Build and run the project. Note that Oledb32.dll truncates the string at the null-termination character, so that the data that is retrieved is as follows:

      Length:6
      Value:41042043
   					

You expect the following results:

         Length:10
         Value:4104204300044