创建dblink操作
客户端：192.168.10.3
服务端：192.168.10.2
前提：客户端想要查找服务端的hr用户下的ft表
SQL> select * from tab;
TNAME TABTYPE CLUSTERID
------------------------------ ------- ----------
COUNTRIES TABLE
DEPARTMENTS TABLE
EMPLOYEES TABLE
EMP_DETAILS_VIEW VIEW
FT TABLE
JOBS TABLE
JOB_HISTORY TABLE
LOCATIONS TABLE
REGIONS TABLE
9 rows selected.
1） 首先检查客户端/服务端的监听是否已经启动：
服务端：
oracle@wang ~]$ lsnrctl status
LSNRCTL for Linux: Version 11.2.0.4.0 - Production on 23-SEP-2016 16:42:59
Copyright (c) 1991, 2013, Oracle. All rights reserved.
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=wang)(PORT=1521)))
STATUS of the LISTENER
------------------------
Alias LISTENER
Version TNSLSNR for Linux: Version 11.2.0.4.0 - Production
Start Date 23-SEP-2016 16:30:32
Uptime 0 days 0 hr. 12 min. 27 sec
Trace Level off
Security ON: Local OS Authentication
SNMP OFF
Listener Parameter File /u01/app/oracle/product/11.2.0/dbhome_1/network/admin/listener.ora
Listener Log File /u01/app/oracle/diag/tnslsnr/wang/listener/alert/log.xml
Listening Endpoints Summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=wang)(PORT=1521)))
Services Summary...
Service "ORA11GR2" has 2 instance(s).
Instance "ORA11GR2", status UNKNOWN, has 1 handler(s) for this service...
Instance "ORA11GR2", status READY, has 1 handler(s) for this service...
Service "ORA11GR2XDB" has 1 instance(s).
Instance "ORA11GR2", status READY, has 1 handler(s) for this service...
The command completed successfully
[oracle@wang ~]$
客户端：
[oracle@bing ~]$ lsnrctl status
LSNRCTL for Linux: Version 11.2.0.4.0 - Production on 23-SEP-2016 16:44:34
Copyright (c) 1991, 2013, Oracle. All rights reserved.
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=bing)(PORT=1521)))
STATUS of the LISTENER
------------------------
Alias LISTENER
Version TNSLSNR for Linux: Version 11.2.0.4.0 - Production
Start Date 23-SEP-2016 16:29:27
Uptime 0 days 0 hr. 15 min. 6 sec
Trace Level off
Security ON: Local OS Authentication
SNMP OFF
Listener Parameter File /u01/app/oracle/product/11.2.0/dbhome_1/network/admin/listener.ora
Listener Log File /u01/app/oracle/diag/tnslsnr/bing/listener/alert/log.xml
Listening Endpoints Summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=bing)(PORT=1521)))
Services Summary...
Service "PROD" has 1 instance(s).
Instance "PROD", status READY, has 1 handler(s) for this service...
Service "PRODXDB" has 1 instance(s).
Instance "PROD", status READY, has 1 handler(s) for this service...
The command completed successfully
[oracle@bing ~]$
2） 在客户端设置tnsname.ora(对服务端网络识别的信息及别名)
[oracle@bing dbs]$ cd /u01/app/oracle/product/11.2.0/dbhome_1/network/admin/
[oracle@bing admin]$ ls
listener.ora samples shrept.lst tnsnames.ora
[oracle@bing admin]$
[oracle@bing admin]$ vi tnsnames.ora
# tnsnames.ora Network Configuration File: /u01/app/oracle/product/11.2.0/dbhome_1/network/admin/tnsnames.ora
# Generated by Oracle configuration tools.
11 =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.10.2)(PORT = 1521))
)
(CONNECT_DATA =
(SERVICE_NAME = ORA11GR2)
)
)
~
"tnsnames.ora" 22L, 509C written
[oracle@bing admin]$
测试：
[oracle@bing admin]$ tnsping 11
TNS Ping Utility for Linux: Version 11.2.0.4.0 - Production on 23-SEP-2016 17:11:41
Copyright (c) 1997, 2013, Oracle. All rights reserved.
Used parameter files:
Used TNSNAMES adapter to resolve the alias
Attempting to contact (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.10.2)(PORT = 1521))) (CONNECT_DATA = (SERVICE_NAME = ORA11GR2)))
OK (10 msec)
[oracle@bing admin]$
3） 在客户端的数据库中创建DBlink：
SQL> create database link ftlink connect to hr identified by hr using '11';
Database link created.
可以将连接字符串'11'换为简便连接的ip:port/service_name(服务端的)。
SQL>
4） 在客户端的数据库内访问服务器端的hr用户下的ft表：
SQL> select count(*) from hr.ft@ftlink;
COUNT(*)
----------
107
验证：
SQL> select instance_name,host_name from v$instance;
INSTANCE_NAME HOST_NAME
---------------- ----------
PROD bing
SQL> desc dba_db_links
Name Null? Type
----------------------------------------- -------- ----------------------------
OWNER NOT NULL VARCHAR2(30)
DB_LINK NOT NULL VARCHAR2(128)
USERNAME VARCHAR2(30)
HOST VARCHAR2(2000)
CREATED NOT NULL DATE
SQL> select OWNER,DB_LINK,USERNAME,HOST,CREATED from dba_db_links;
OWNER DB_LINK USERNAME HOST CREATED
----- -------- -------- -------- ------------------------------------------------
SYS FTLINK HR 11 23-SEP-16
总结：DBlink就是登陆到本地数据库，可以以dblink的方式访问其他数据库用户下的信息的一种网络间通信方法。