Common table expression

A Common Table Expression (in SQL) is a temporary named result set, derived from a simple query and defined within the execution scope of a SELECT, INSERT, UPDATE, or DELETE statement.

CTE can be thought of as an alternatives to derived tables (subquery), views, and inline user-defined functions.

External links

• Getting in the loop with CTEs
• MSDN tutorial
• Tony Rogerson's Blog entry on how CTE's work and how to do recursion using an adjancey list as an example in Microsoft SQL Server