DataTable and Relational Operators
DavidM is running some interesting notes on DataTable Relational Operators (in C#) -- Introduction, JOIN, UNION, DISTINCT helper method, DIFFERENCE / MINUS, PRODUCT, DIVIDE, PROJECT. Each of these methods have various overloaded signatures and could easily be extended. David will dedicate a post for each of these operators.
Also, a new article by Bipin Joshi elaborates on how to Synchronize Identity Values between Database and DataSet During Updates - After inserting the rows in the database your DataTable does not automatically reflect the identity values of as assigned by the database. The problem can be solved by the clever use of stored procedures and output parameters.