oracle的dblink创建连接查询及使用
https://www.cnblogs.com/muhai/p/15527463.html
https://www.cnblogs.com/leipei2352/archive/2011/04/21/2023471.html
https://www.cnblogs.com/muhai/p/15527463.html
https://www.cnblogs.com/leipei2352/archive/2011/04/21/2023471.html