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 RainbowResearchgoCreate Schema RaingoCreate Schema SnowgoCreate table Rainbowresearch.Rain.Cities (id int, City varchar(200))goinsert 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‘goCreate procedure Rain.DisplayCities @id intasSelect City from Rainbowresearch.Rain.Cities where id=@idgoCreate table Rainbowresearch.Snow.Cities (id int, City varchar(200))goinsert 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‘goCreate procedure Snow.DisplayCities @id intasSelect City from Rainbowresearch.Snow.Cities where id=@idgoUse RiverResearchgoCreate Schema RivergogoCreate table RiverResearch.River.Cities (id int, City varchar(200))goinsert 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‘goCreate procedure River.DisplayCities @id intasSelect City from RiverResearch.River.Cities where id=@idGo 

 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.Citiesgoselect * from Rainbowresearch.Rain.Citiesgoselect * from Rainbowresearch.Snow.Citiesgo

最后，我们建立同义词

use RainbowResearchgocreate SYNONYM  RiverCities for RiverResearch.River.Citiesgocreate SYNONYM  RainCities for Rainbowresearch.Rain.Citiesgocreate SYNONYM  SnowCities for Rainbowresearch.Snow.Citiesgouse RiverResearchgocreate SYNONYM  RiverCities for RiverResearch.River.Citiesgocreate SYNONYM  RainCities for Rainbowresearch.Rain.Citiesgocreate SYNONYM  SnowCities for Rainbowresearch.Snow.Citiesgo

看到了么，简单许多了

再来查询一次，这次简单多了

Use RiverResearchgoSelect * from RiverCitiesSelect * from RainCitiesSelect * from SnowCitiesGoUse RainbowResearchgoSelect * from RiverCitiesgoSelect * from RainCitiesgoSelect * from SnowCitiesgo

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