如何在Oracle里設置訪問多個SQL Server數據庫？假設我們要在ORACLE里同時能訪問SQL Server里默認的pubs和Northwind兩個數據庫。
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)里訪問Microsoft SQL Server數據庫
ORACLE9I_HOMEg4msqladmin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=OFFHS_FDS_RECOVERY_ACCOUNT=RECOVERHS_FDS_RECOVERY_PWD=RECOVERinitnorthwind.ora內容如下:HS_FDS_CONNECT_INFO="SERVER=sqlserver_hostname;DATABASE=Northwind"HS_DB_NAME=NorthwindHS_FDS_TRACE_LEVEL=OFFHS_FDS_RECOVERY_ACCOUNT=RECOVERHS_FDS_RECOVERY_PWD=RECOVER$ORACLE9I_HOMEetworkadmin 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) ) ) |
重啟動這臺做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后,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） |
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下數據庫里的數據:
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 位于第 1 行:ORA-00904: 無效列名select "zip" from stores;zip-----980569278996745980149001989076 |
已選擇6行
用SQL Navigator或Toad看從SQL Server轉移到ORACLE里的表的建表語句為:
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_HOMEg4msqladmin目錄下的initsqlserver_databaseid.ora
WINDOWS下ORACLE9i網關服務器listener.ora里面
(SID_DESC= (SID_NAME=sqlserver_databaseid) (ORACLE_HOME=d:OracleOra92) (PROGRAM=tg4msql) ) UNIX或WINDOWS下ORACLE8I,ORACLE9I服務器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.
