create public database link 名称
? connect to 用户名 identified by 密码
? using '(DESCRIPTION =
? ? (ADDRESS = (PROTOCOL = TCP)(HOST = IP地址)(PORT = 1521))
? ? (CONNECT_DATA =
? ? ? (SERVER = DEDICATED)
? ? ? (SERVICE_NAME = SID)
? ? )
? )';

?

11g 区分大小写 ?账号 密码 加双引号