Heath does an excellent job detailing this: http://blogs.msdn.com/heath
The following link contains a list of Microsoft SQL Server data types and a list of their .NET CLR equivalents: http://msdn2.microsoft.com/... And this link shows the mapping between C# built-in types and the .NET CLR types: http://msdn2.microsoft.com/...
When you're developing .NET apps the .NET security can be a right pain in the butt, so to avoid any more head aches you can simply turn it off by using the caspol utility eg: caspol -s off While this is somewhat overkill (much like cutting your toe nails with a sythe), it certainly gets you up and running in no time. However the problems come when you start moving from your dev platform, onto testing & prod environments. But hopefully with you'll implement a more thorough approach. This works...