SET ANSI_NULLS ON的含义 [英] meaning of SET ANSI_NULLS ON

问题描述

朋友....

我想知道
的意思

Hi Friends....

I want to know the meaning of

SET ANSI_NULLS ON     

AND

SET QUOTED_IDENTIFIER ON

推荐答案

您可以从链接中查看

http://blog.sqlauthority.com/2007 /03/05/sql-server-quoted_identifier-onoff-and-ansi_null-onoff-explanation/ [

You can check from the links

http://blog.sqlauthority.com/2007/03/05/sql-server-quoted_identifier-onoff-and-ansi_null-onoff-explanation/[^]

http://praveenbattula.blogspot.com/2009/05/use-of-set-ansinulls-on-in-sql-server.html

ANSI_NULLS ON

This option specifies the setting for ANSI NULL comparisons. When this is on, any query that compares a value with a null returns a 0. When off, any query that compares a value with a null returns a null value.

QUOTED IDENTIFIER ON/OFF:
This options specifies the setting for usage of double quotation. When this is on, double quotation mark is used as part of the SQL Server identifier (object name). This can be useful in situations in which identifiers are also SQL Server reserved words.

当

SET ANSI_NULLS ON

表示正在遵循ISO标准.
表示
=和<>不应用于空比较.

如果要使用= or <>进行空比较，请使用

it means ISO Standard is being followed.
means
= and <> should not be used for null comparison.

If you want to use = or <> for null comparison use

SET ANSI_NULLS OFF

表示不遵循ISO标准.

it means do not follow ISO Standard.

SET ANSI_NULLS

应该设置为ON以执行分布式查询
用于维护服务器之间查询的兼容性.

和

QUOTED_IDENTIFIER
它指定SQL Server如何处理单引号和双引号中定义的数据.当将其设置为ON时，双引号"中定义的任何字符集都将被视为T-SQL标识符(表名称，过程名称，列名称….etc)，并且命名标识符的T-SQL规则将不被使用.适用于它.并且在单引号'中定义的任何字符集都被视为文字.

should be set to ON for executing distributed queries
for maintaining compatibility of queries accross Servers.

and

QUOTED_IDENTIFIER
It specifies how SQL Server treats the data that is defined in Single Quotes and Double Quotes. When it is set to ON any character set that is defined in the double quotes "" is treated as a T-SQL Identifier (Table Name, Proc Name, Column Name….etc) and the T-SQL rules for naming identifiers will not be applicable to it. And any character set that is defined in the Single Quotes ‘’ is treated as a literal.

请参阅以下内容:

http://stackoverflow.com/questions/9766717/in-sql-server-what-does-set-ansi-nulls-on-means [ http://msdn.microsoft.com/en-us/library/ms188048.aspx [ ^ ]

Refer these:

http://stackoverflow.com/questions/9766717/in-sql-server-what-does-set-ansi-nulls-on-means[^]


http://msdn.microsoft.com/en-us/library/ms188048.aspx[^]

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