在sql server中使用with子句 [英] with clause in sql server

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本文介绍了在sql server中使用with子句的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!

问题描述

我可以在sql中给出简单的with子句示例吗?



我们应该在哪里使用它?

解决方案

你可以使用它来允许选择脏读;



 选择 * 来自 my_table  with  nolock 其中 condition = ' 某事' 





希望这会有所帮助,

Fredrik


< blockquote>

  WITH  Sales_CTE(SalesPersonID,NumberOfOrders)
AS

SELECT SalesPersonID,COUNT(*)
FROM 销售.SalesOrderHeader
WHERE Sa lesPersonID IS NOT NULL
GROUP BY SalesPersonID

SELECT AVG(NumberOfOrders) AS 平均值每人销售额
FROM Sales_CTE;
GO





进一步了解MSDN:



http://technet.microsoft.com/en -us / library / ms175972.aspx [ ^ ]

Can one give me simple example of with clause in sql ?

And Where should we use this ?

解决方案

You can use it to allow dirty reads in a select for example;

select * from my_table with(nolock) where condition='something'



Hope this helps,
Fredrik


WITH Sales_CTE (SalesPersonID, NumberOfOrders)
AS
(
    SELECT SalesPersonID, COUNT(*)
    FROM Sales.SalesOrderHeader
    WHERE SalesPersonID IS NOT NULL
    GROUP BY SalesPersonID
)
SELECT AVG(NumberOfOrders) AS "Average Sales Per Person"
FROM Sales_CTE;
GO



Look further at MSDN:

http://technet.microsoft.com/en-us/library/ms175972.aspx[^]


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