# Oracle dblink应用

select owner,object_name from dba_objects where object_type='DATABASE LINK';
or
select * from dba_db_links;

前提: 创建dblink的用户有对应的数据库权限

create public database link 或者create database link ;
grant create public database link,create database link to myAccount;
create public database link dblinkname connect to username identified by password
   using '(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = database_ip)(PORT = 1521))
)
(CONNECT_DATA =
(SERVICE_NAME =servicename)
)
)';

如果在create之后不加public,则创建的dblink就不是公共的,就只有创建者可以使用了.

  • 如何确定数据库的servicename:
  1. sqlplus中使用
show parameter[s] service_names;

注意parameter和parameters都可以 或者

select name,value from v$parameter where name='service_names';

例如,在本机数据库上创建了一个scott_rmthost的public dblink(使用远程主机的scott用户连接),则用sqlplus连接到本机数据库,执行select * from scott.emp@scott_rmthot即可以将远程数据库上的scott用户下的emp表中的数据获取到. 也可以在本地建一个同义词来指向scott.emp@scott_rmthost,这样取值就方便多了.

drop public database link dblinkname;

例:

create public database link chengwenit connect to chengweniterp
identified by "123456"    using '(DESCRIPTION = (ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.11.102)(PORT = 1521)) )
(CONNECT_DATA = (SERVICE_NAME =CWIT) ) )';