How can I fetch data in a Winforms application or ASP.NET form from a SAP database? The .NET framework used is 2.0. , language is C# and SAP version is 7.10.
Not sure if this will work for you, but there's a C library, which can probably be used from your C# application and which provides a quite easy API for calling BAPIs in SAP. (Accessing the underlying database directly via SQL is not to be recommended... Better use BAPIs or a custom-tailored RFC-enabled function module.) See http://service.sap.com/rfc-library
You may also be able to use the "SAP connector for Microsoft .NET" (from the same link above), but it was developed with .NET 1.1 and may have compatibility problems with .NET 2.0?!
Update (2011): Since Dec. 2010 there is a new version of the "SAP connector for Microsoft .NET" available, which works with .NET Frameworks 2.0, 3.5 and 4.0. This would now be the perfect solution for your question! See http://service.sap.com/connectors ---> SAP connector for Microsoft .NET