创建 database link

1.

create database link "ORA111"

connect to system
identified by oracle
using 'orcl';

2.

create database link "ORA111"

connect to system
identified by oracle
using '(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=172.17.3.111)(PORT=1521)))(CONNECT_DATA=(SID=orcl)))';