**********创建数据库链接******************

create public database link link_gzzl

connect to system identified by "123456"

using '(DESCRIPTION =

(ADDRESS_LIST =

(ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.20)(PORT = 1521))

)

(CONNECT_DATA =

(SERVICE_NAME = GZZL)

)

)';

***********从A库取B库的数据

select * from pat_master_index@likn_gzzl;