在Oracle里设置访问多个SQL Server
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               作者:佚名 
                来源:InterNet 加入时间:2005-1-31                       | 
                   
                   
                    
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如何在Oracle里设置访问多个SQL Server数据库?假设我们要在ORACLE里同时能访问SQL Server里默认的pubs和Northwind两个数据库。 
  1、在安装了ORACLE9i Standard Edition或者ORACLE9i Enterprise Edition的windows机器上(IP:192.168.0.2), 产品要选了透明网关(Oracle Transparent Gateway)里访问Microsoft SQL Server数据库 
  
$ORACLE9I_HOME\tg4msql\admin下新写initpubs.ora和initnorthwind.ora配置文件.
initpubs.ora内容如下:
HS_FDS_CONNECT_INFO="SERVER=SQLSERVER_HOSTNMAE;DATABASE=pubs"
HS_DB_NAME=pubs
HS_FDS_TRACE_LEVEL=OFF
HS_FDS_RECOVERY_ACCOUNT=RECOVER
HS_FDS_RECOVERY_PWD=RECOVER
initnorthwind.ora内容如下:
HS_FDS_CONNECT_INFO="SERVER=sqlserver_hostname;DATABASE=Northwind"
HS_DB_NAME=Northwind
HS_FDS_TRACE_LEVEL=OFF
HS_FDS_RECOVERY_ACCOUNT=RECOVER
HS_FDS_RECOVERY_PWD=RECOVER
$ORACLE9I_HOME\network\admin 下listener.ora内容如下:
LISTENER =
  (DESCRIPTION_LIST =
   (DESCRIPTION =
    (ADDRESS_LIST =
    (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.0.2)(PORT = 1521))
  )
  )
  )
SID_LIST_LISTENER =
  (SID_LIST =
  (SID_DESC =
  (GLOBAL_DBNAME = test9)
  (ORACLE_HOME = d:\oracle\ora92)
  (SID_NAME = test9)
 )
  (SID_DESC=
  (SID_NAME=pubs)
  (ORACLE_HOME=d:\Oracle\Ora92) 
  (PROGRAM=tg4msql)
  )
  (SID_DESC=
  (SID_NAME=northwind)
  (ORACLE_HOME=d:\Oracle\Ora92) 
 (PROGRAM=tg4msql)
    )
  )  |   
  重启动这台做gateway的windows机器上(IP:192.168.0.2)TNSListener服务. 
  (凡是按此步骤新增可访问的SQL Server数据库时,TNSListener服务都要重启动) 
  2、ORACLE8I,ORACLE9I的服务器端配置tnsnames.ora, 添加下面的内容: 
  
pubs =
  (DESCRIPTION =
  (ADDRESS_LIST =
    (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.0.2)(PORT = 1521))
    )
    (CONNECT_DATA =
    (SID = pubs)
    )
    (HS = pubs) 
   )
   
northwind =
  (DESCRIPTION =
  (ADDRESS_LIST =
 (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.0.2)(PORT = 1521))
    )
    (CONNECT_DATA =
    (SID = northwind)
    )
    (HS = northwind) 
   )   
 保存tnsnames.ora后,在命令行下
 tnsping pubs
 tnsping northwind  |   
  出现类似提示,即为成功 
  
Attempting to contact (DESCRIPTION = (ADDRESS_LIST = 
(ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.0.2)
(PORT = 1521))) (CONNECT_DATA = (SID = pubs)) (HS = pubs))
OK(20毫秒)
Attempting to contact (DESCRIPTION = (ADDRESS_LIST =
 (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.0.2)
(PORT = 1521))) (CONNECT_DATA = (SID = northwind)) (HS = northwind))
OK(20毫秒)  |   
  设置数据库参数global_names=false。 
  设置global_names=false不要求建立的数据库链接和目的数据库的全局名称一致。global_names=true则要求, 多少有些不方便。 
  oracle9i和oracle8i都可以在DBA用户下用SQL命令改变global_names参数 
  
alter system set global_names=false;  |   
  建立公有的数据库链接: 
  
create public database link pubs 
connect to testuser identified by testuser_pwd using 'pubs';
create public database link northwind 
connect to testuser identified by testuser_pwd using 'northwind';
(假设SQL Server下pubs和northwind已有足够权限的用户登陆testuser,
密码为testuser_pwd)  |   
  访问SQL Server下数据库里的数据: 
  
select * from stores@pubs;
...... 	......
select * from region@northwind;
......  ......  |   
  3、使用时的注意事项 
  ORACLE通过访问SQL Server的数据库链接时,用select * 的时候字段名是用双引号引起来的。 
  例如: 
  
create table stores as select * from stores@pubs;
select zip from stores;
ERROR 位于第 1 行:
ORA-00904: 无效列名
select "zip" from stores;
zip
-----
98056
92789
96745
98014
90019
89076  |   
  已选择6行。 
  用SQL Navigator或Toad看从SQL Server转移到ORACLE里的表的建表语句为: 
  
CREATE TABLE stores
    ("stor_id"                      CHAR(4) NOT NULL,
    "stor_name"                    VARCHAR2(40),
    "stor_address"                 VARCHAR2(40),
    "city"                         VARCHAR2(20),
    "state"                        CHAR(2),
    "zip"                          CHAR(5))
  PCTFREE     10
  PCTUSED     40
  INITRANS    1
  MAXTRANS    255
  TABLESPACE  users
  STORAGE   (
    INITIAL     131072
    NEXT        131072
    PCTINCREASE 0
    MINEXTENTS  1
    MAXEXTENTS  2147483645
  )
/  |   
  总结: 
  WINDOWS下ORACLE9i网关服务器在$ORACLE9I_HOME\tg4msql\admin目录下的initsqlserver_databaseid.ora 
  WINDOWS下ORACLE9i网关服务器listener.ora里面 
  
(SID_DESC=
     		(SID_NAME=sqlserver_databaseid)
      		(ORACLE_HOME=d:\Oracle\Ora92) 
      		(PROGRAM=tg4msql)
   	)
   	UNIX或WINDOWS下ORACLE8I,ORACLE9I服务器tnsnames.ora里面
	northwind =
	  (DESCRIPTION =
(ADDRESS_LIST =
	(ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.0.2)(PORT = 1521))
	    )
	(CONNECT_DATA =
	(SID = sqlserver_databaseid)
    		)
	(HS = sqlserver_databaseid) 
   	   )  |   
  sqlserver_databaseid一致才行. 
 
               
              [文章录入员:nancy] | 
                                      
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