SQL SERVER 2005中同义词实例
From : http://www.cnblogs.com/jackyrong/archive/2006/11/15/561287.html
在SQL SERVER 2005中,终于出现了同义词了,大大方便了使用。下面举个小例子说明
同义词是用来实现下列用途的数据库对象:
为本地或远程服务器上的另一个数据库对象(称为“基对象”)提供备选名称。
提供一个提取层,该层防止客户端应用程序的基对象的名称或位置被更改。
例如,名为 Server1 的服务器上有 Adventure Works 的 Employee 表。若要从另一台服务器 Server2 引用此表,客户端应用程序必须使用由四个部分构成的名称 Server1.AdventureWorks.Person.Employee。另外,如果更改了表的位置(例如,更改到另一台服务器上),那么需要修改客户端应用程序以反映所做的更改。 之前在http://www.cnblogs.com/jackyrong/archive/2006/06/15/426304.html中已经归纳了一些特性,现在在举出例子,例子来自老外的。
首先建立两个数据库
Create Database RiverResearch
go
Use RiverResearch
go
然后分别为两个数据库建立模式以及表,存储过程如下
Use RainbowResearch go Create Schema Rain go Create Schema Snow go Create table Rainbowresearch.Rain.Cities (id int, City varchar(200)) go insert into Rainbowresearch.Rain.Cities select 1, ‘Hongkong‘ insert into Rainbowresearch.Rain.Cities select 2, ‘Tokyo‘ insert into Rainbowresearch.Rain.Cities select 3, ‘Beijing‘ insert into Rainbowresearch.Rain.Cities select 4, ‘Taipei‘ insert into Rainbowresearch.Rain.Cities select 5, ‘Seoul‘ insert into Rainbowresearch.Rain.Cities select 6, ‘Mumbai‘ go Create procedure Rain.DisplayCities @id int as Select City from Rainbowresearch.Rain.Cities where id=@id go Create table Rainbowresearch.Snow.Cities (id int, City varchar(200)) go insert into Rainbowresearch.Snow.Cities select 1, ‘Tokyo‘ insert into Rainbowresearch.Snow.Cities select 2, ‘Seoul‘ insert into Rainbowresearch.Snow.Cities select 3, ‘Moscow‘ insert into Rainbowresearch.Snow.Cities select 4, ‘NewYork‘ go Create procedure Snow.DisplayCities @id int as Select City from Rainbowresearch.Snow.Cities where id=@id go Use RiverResearch go Create Schema River go go Create table RiverResearch.River.Cities (id int, City varchar(200)) go insert into RiverResearch.River.Cities select 1, ‘Hongkong‘ insert into RiverResearch.River.Cities select 2, ‘Tokyo‘ insert into RiverResearch.River.Cities select 3, ‘Beijing‘ insert into RiverResearch.River.Cities select 4, ‘Taipei‘ insert into RiverResearch.River.Cities select 5, ‘Seoul‘ go Create procedure River.DisplayCities @id int as Select City from RiverResearch.River.Cities where id=@id Go
这里,在RainbowResearch数据库里建立了两个模式,rain,snow,再分别在这两个模式下建立了city表,而在
riversearch数据库里也建立了个模式river,也建立了表cities,就这么简单,不详细表述。
之后,我们查询刚才建好的内容
select * from RiverResearch.River.Cities go select * from Rainbowresearch.Rain.Cities go select * from Rainbowresearch.Snow.Cities go
最后,我们建立同义词
use RainbowResearch go create SYNONYM RiverCities for RiverResearch.River.Cities go create SYNONYM RainCities for Rainbowresearch.Rain.Cities go create SYNONYM SnowCities for Rainbowresearch.Snow.Cities go use RiverResearch go create SYNONYM RiverCities for RiverResearch.River.Cities go create SYNONYM RainCities for Rainbowresearch.Rain.Cities go create SYNONYM SnowCities for Rainbowresearch.Snow.Cities go
看到了么,简单许多了
再来查询一次,这次简单多了
Use RiverResearch go Select * from RiverCities Select * from RainCities Select * from SnowCities Go Use RainbowResearch go Select * from RiverCities go Select * from RainCities go Select * from SnowCities go
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