在實際的操作中你對Oracle中設置訪問N個SQL Server數據庫的實際操作是否滿頭霧水?如果我們要在Oracle同時訪問N個SQL Server中默認的pubs與Northwind兩個數據庫。那麼我們應該如何操作呢?
1、在安裝了Oracle9i Standard Edition或者Oracle9i Enterprise Edition的Windows機器上(IP:192.168.0.2), 產品要選了透明網關(Oracle Transparent Gateway)裡訪問Microsoft SQL Server據庫
Oracle9I_HOMEtg4msqladmin下新寫initpubs.ora和initnorthwind.ora配置文件.initpubs.ora內容如下:
- HS_FDS_CONNECT_INFO="SERVER=SQLSERVER_HOSTNMAE; DATABASE=pubs"
- HS_DB_NAME=pubsHS_FDS_TRACE_LEVEL=OFF
- HS_FDS_RECOVERY_ACCOUNT=RECOVER
- HS_FDS_RECOVERY_PWD=RECOVER
initnorthwind.ora內容如下:
- 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_HOMEnetworkadmin 下listener.ora
內容如下:
- 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:Oracleora92)
- (SID_NAME = test9)
- )
- (SID_DESC=
- (SID_NAME=pubs)
- (Oracle_HOME=d:OracleOra92)
- (PROGRAM=tg4msql)
- )
- (SID_DESC=
- (SID_NAME=northwind)
- (Oracle_HOME=d:OracleOra92)
- (PROGRAM=tg4msql)
- )
- )
重啟動這台做gateway的Windows機器上(IP:192.168.0.2)TNSListener服務(凡是按此步驟新增可訪問的SQL Server數據庫時,TNSListener服務都要重啟動)。
2、Oracle8i,Oracle9i的服務器端配置tnsnames.ora, 添加下面的內容:
- 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後,在命令行下
- tnsping pubs
- tnsping northwind
出現類似提示,即為成功:
- 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)
Oracle同時訪問中設置數據庫參數global_names=false。設置global_names=false不要求建立的數據庫鏈接和目的數據庫的全局名稱一致。global_names=true則要求, 多少有些不方便。 oracle9i和Oracle8i都可以在DBA用戶下用SQL命令改變global_names參數
- alter system set global_names=false;
建立公有的數據庫鏈接:
- 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';
(假設SQL Server下pubs和northwind已有足夠權限的用戶登陸testuser,密碼為testuser_pwd) 訪問SQL Server下數據庫裡的數據:
- select * from stores@pubs;
- ...... ......select *
- from region@northwind;
3、使用時的注意事項
Oracle通過訪問SQL Server的數據庫鏈接時,用select * 的時候字段名是用雙引號引起來的。例如:
- create table stores as select * from stores@pubs;
- select zip from stores;
ERROR 位於第 1 行:ORA-00904: 無效列名
- select "zip" from stores;
- zip
- -----
- 98056
- 92789
- 96745
- 98014
- 90019
- 89076
已選擇6行,用SQL Navigator或Toad看從SQL Server轉移到Oracle裡的表的建表語句為:
- 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
- )
總結:
Windows下Oracle9i網關服務器在$Oracle9i_HOMEtg4msqladmin目錄下的initsqlserver_databaseid.ora。Windows下Oracle9i網關服務器listener.ora裡面:
- (SID_DESC=
- (SID_NAME=sqlserver_databaseid)
- (Oracle_HOME=d:OracleOra92)
- (PROGRAM=tg4msql)
- )
上述的相關內容就是對使Oracle同時訪問多個SQL Server的描述,希望會給你帶來一些幫助在此方面。