用VS 连接数据库连不上去

[silversward]

照着教材写了数据库连接的代码，结果代码不报错但是连不上去，求大神救命

void loadDBinfor()
{
	SQLRETURN re;
	SQLHENV henv;  //环境句柄
	SQLHDBC hdbc;//连接句柄
	SQLHSTMT hstmt;//语句句柄
	re = SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &henv);
	re = SQLSetEnvAttr(henv, SQL_ATTR_ODBC_VERSION, (SQLPOINTER)SQL_OV_ODBC3, SQL_IS_INTEGER);//初始化环境
	re = SQLAllocHandle(SQL_HANDLE_DBC, henv, &hdbc);
	re = SQLConnect(hdbc, (SQLCHAR*)"M_market", SQL_NTS, (SQLCHAR*)"sa", SQL_NTS, (SQLCHAR*)"123456", SQL_NTS);
	if (re == SQL_SUCCESS || re == SQL_SUCCESS_WITH_INFO)
	{
		cout << "数据库连接成功！" << endl;
	}
	else
	{
		cout << "连接失败！" << endl;
	}
}