CREATE PUBLIC DATABASE LINK XX_DBLINK CONNECT TO 用户名（小写） IDENTIFIED BY 密码（小写） USING '(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = 目标数据库IP)(PORT = 目标数据库端口))
)
(CONNECT_DATA =
(SERVICE_NAME = 目标数据库服务名)
)
)'