There are various methods to connect to SQL Server:
For native code (C/C++), the recommended way is to use ODBC. Please use SQL
Server Native Client 10.0, which can be downloaded from "Microsoft SQL Server
2008 Native Client" at
http://www.microsoft.com/downloads/details.aspx?FamilyId=C6C3E9EF-BA29-4A43-8D69-A2BED18FE73C&displaylang=en
For managed code (C#), you can use ADO.NET.
It also supports the connectivity via PHP, Java, etc.
Thanks,
Ming.
WDAC Team, Microsoft.
P.S. We recommend customers to use the forum to ask questions in the future,
where you can obtain a faster response (Forum is at:
http://social.msdn.microsoft.com/forums/en-US/sqldataaccess/threads/)