Parametrized ADO Stored Procedure from C++

[Ajaxx]

I’m trying to call a stored procedure on my SQL 2008 server with the below code. When I look at the query with the SQL profiler I get the following:

exec GetUserID @Email='test@email.com',@Password='@Email'

What I expect to get is:

exec GetUserID @Email='test@email.com',@Password='123456'

Can someone explain what is going on please?

#include "stdafx.h"

#import "C:\Program Files\Common Files\System\ado\msado15.dll" rename("EOF", "EndOfFile")

int _tmain(int argc, _TCHAR* argv[])
{
	try
	{
		::CoInitialize(NULL);

		ADODB::_ConnectionPtr ConnectionPtr = NULL;
		ADODB::_CommandPtr CommandPtr = NULL;
		ADODB::_ParameterPtr ParameterPtr = NULL;
		
		char ConnectionString[200] = "Provider=SQLNCLI10; Server=IL47WS030501; Database=Demo; Trusted_Connection=yes;";

		ConnectionPtr.CreateInstance(__uuidof(ADODB::Connection));

		if(ConnectionPtr)
		{
			ConnectionPtr->Open(ConnectionString, "", "", 0);
		}

		CommandPtr.CreateInstance(__uuidof(ADODB::Command));

		if(ConnectionPtr && CommandPtr)
		{
			CommandPtr->ActiveConnection = ConnectionPtr;
			CommandPtr->CommandType = ADODB::adCmdStoredProc;
			CommandPtr->CommandText = _bstr_t("GetUserID");
			CommandPtr->NamedParameters = true;

			VARIANT vEmail;
			vEmail.vt = VT_BSTR;
			vEmail.bstrVal = _bstr_t("test@email.com");

			VARIANT vPassword;
			vPassword.vt = VT_BSTR;
			vPassword.bstrVal = _bstr_t("123456");

			CommandPtr->Parameters->Append(CommandPtr->CreateParameter(_bstr_t("@Email"), ADODB::adVarChar, ADODB::adParamInput, sizeof(vEmail), vEmail));
			CommandPtr->Parameters->Append(CommandPtr->CreateParameter(_bstr_t("@Password"), ADODB::adVarChar, ADODB::adParamInput, sizeof(vPassword), vPassword));

			ADODB::_RecordsetPtr RecordsetPtr = CommandPtr->Execute(NULL, NULL, ADODB::adCmdStoredProc);
		}

		return 0;
	}
	catch(...)
	{
	}
}

[Ajaxx]

I don’t know the details of why but I was able to get it working using the following code without a VARIANT instead:

CommandPtr->Parameters->Append(CommandPtr->CreateParameter(_bstr_t("@Email"), ADODB::adVarChar, ADODB::adParamInput, 50, "test@email.com"));
CommandPtr->Parameters->Append(CommandPtr->CreateParameter(_bstr_t("@Password"), ADODB::adVarChar, ADODB::adParamInput, 50, "123456"));