谨以本帖,献给我温柔善良,豪气大方的山东妹子,我的导师Asa(421073390,情感交友版主,很任性的那位);
我的搭档小友,风流倜傥,英俊潇洒,即将步入社会的量化投资版主fantuanxiaot。
特别鸣谢免费大师,管理科学版主感谢kychan一直以来的无私奉献。
因为有你,量化投资更精彩!
谢谢人大论坛平台!
感恩,因为有你
完美收官,谢谢大家
本帖隐藏的内容
Stairway to Advanced T-SQL Level 3: Understanding Common Table Expressions (CTEs)
2015/03/18
(http://www.sqlservercentral.com/articles/Stairway+Series/122606/)
The Series
This article is part of the Stairway Series: Stairway to Advanced T-SQL
This stairway will contain a series of articles that will expand on the T-SQL foundation that you learned in the prior two T-SQL stairways, Stairway to T-SQL DML and T-SQL Beyond the Basics. This stairway should help readers prepare for passing the Microsoft Certification exam 70-461: Querying Microsoft SQL Server 2012.
With the rollout of SQL Server 2005, Microsoft introduced a new query construct called a common table expression (CTE). A CTE is a temporary result set defined by a simple query, and is used within the execution scope of a single INSERT, UPDATE, DELETE, or SELECT statement. In this article I be exploring how to define and use CTE's.
Defining and Using CTE's
With the introduction of CTE's by Microsoft you now have a different way to build and document complex pieces of TSQL code. By using a CTE you can write and name a TSQL SELECT statement and then reference the named statement later on much like you would reference a table or a view.
Below is the syntax for defining a CTE:
WITH <expression_name> (Column1, Column2, …) AS (CTE Definition)
Where: