数据库链路创建方法

学习了：http://www.linuxidc.com/Linux/2010-08/27595.htm

删除数据库链接：drop database link linkname;创建数据库链接：create database link linknameconnect to usernameidentified by passwordusing 'connection string';如果想建立全局链接，则需要使用关键字：publiccreate public database link linknameconnect to usernameidentified by passwordusing 'connection string';connection string可以有两种形式：1，在文件tnsnames.ora配置的名称：如：CDRDL =(DESCRIPTION =(ADDRESS_LIST =(ADDRESS = (PROTOCOL = TCP)(HOST = 10.147.129.29)(PORT = 2521)))(CONNECT_DATA =(SERVICE_NAME = cdrdb)))此时可以写成：create database link linknameconnect to usernameidentified by passwordusing 'CDRDL';2，也可以直接使用‘=’号后面的字符串，如：create database link linknameconnect to usernameidentified by passwordusing '(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=10.147.129.29)(PORT=2521)))(CONNECT_DATA=(SERVICE_NAME=cdrdb)))';