Retrieving Variant Column Datatype Using SQLColAttrubute

Hi,
When i try to retirve the datatype of a variant column using SQLColAttribute, the datatype comes back as SQL_BINARY(-2) instead of a CHAR based type. To reproduce the problem, add extended property 'MS_Description' to either a column or a table. Assign a text value to the property.


Execute the following query and verify. SELECT value FROM sys.extended_properties WHERE name = 'MS_Description'

I'm using SQL Server 2005 sp 2 with Visual Studio 2005.

Here is the code i use -




Code Block
SQLHENV m_SQLEnvironment;
SQLHDBC m_SQLConnection;
SQLHSTMT m_SQLStatement;
SQLRETURN iReturn;
CString sConnectionString = _T("DRIVER={SQL Native Client};SERVER=YourServer;DATABASE=YourDatabase;Trusted_Connection=yes;");

CString sQuery = _T("SELECT value FROM sys.extended_properties WHERE name = 'MS_Description'") ;

iReturn = SQLAllocHandle( SQL_HANDLE_ENV,SQL_NULL_HANDLE,&m_SQLEnvironment);
iReturn = SQLSetEnvAttr(m_SQLEnvironment,SQL_ATTR_ODBC_VERSION,(SQLPOINTER) SQL_OV_ODBC3,0);
iReturn = SQLAllocHandle(SQL_HANDLE_DBC,m_SQLEnvironment,&m_SQLConnection);
iReturn = SQLAllocHandle(SQL_HANDLE_STMT, m_SQLConnection, &m_SQLStatement );
SQLCHAR szwOutputConnectionString[800];
SQLSMALLINT nOutputStringLength = 0;
SQLUSMALLINT nDriverCompletion = SQL_DRIVER_NOPROMPT;
iReturn = SQLDriverConnect( m_SQLConnection, m_hWnd, (SQLCHAR*)(LPCSTR)sConnectionString, SQL_NTS, szwOutputConnectionString, 800, &nOutputStringLength, nDriverCompletion );

iReturn = SQLAllocHandle( SQL_HANDLE_STMT,m_SQLConnection,&m_SQLStatement);
iReturn = SQLPrepare( m_SQLStatement, (SQLCHAR*)(LPCSTR)sQuery , SQL_NTS );
iReturn = SQLExecute( m_SQLStatement );
iReturn = SQLFetch( m_SQLStatement );
SQLINTEGER nType = 0;
SQLSMALLINT nDummyInt = 0;

//get the datatype of the variant
iReturn = SQLColAttribute( m_SQLStatement, (SQLUSMALLINT) 1, SQL_CA_SS_VARIANT_TYPE, NULL, NULL, &nDummyInt, &nType );







After the execution of SQLColAttribute, nType value is assigned a value of -2 (SQL_BINARY) instead of a CHAR based type. What am i doing wrong? Any help is appreciated.



Regards,
Venkat