求解释linq语句

Question

Customer 与 SalesOrderHeader 有主外键关系
 var query1 = db.Customers.Where(c => c.Person.LastName == "Zhou");
 var query2 = db.Customers.Where(c => c.Person.LastName == "Zhou").Select(c => c.SalesOrderHeaders);
 var query3 = db.Customers.Where(c => c.Person.LastName == "Zhou").SelectMany(c => c.SalesOrderHeaders);
求解释这3句查询出来有何区别？后两者看不懂。

Answer 1

 第一個會返回 Customers，第二和第三個返回 SalesOrderHeaders。
 
 而 Select 和 SelectMany 的分別，你可以參考這個網頁
http://codingsense.wordpress.com/2008/09/16/differnce-between-select-and-selectmany-in-linq/

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Answer 2

 第一個會返回 Customers，第二和第三個返回 SalesOrderHeaders。
 
 而 Select 和 SelectMany 的分別，你可以參考這個網頁
http://codingsense.wordpress.com/2008/09/16/differnce-between-select-and-selectmany-in-linq/

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大家一齊探討、學習和研究，謝謝！
MCSD, MCAD, MCSE+I, MCDBA, MCDST, MCSA, MCTS, MCITP, MCPD,
MCT, Microsoft Community Star(TW & HK),
Microsoft MVP for VB.NET since 2003
My MSMVP Blog

链接是坏的，没网页

Answer 3

链接好用的哦

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Mike Feng
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