sqlplus /@course as sysdba;
show con_name;
show pdbs;
sqlplus /@orcl as sysdba;中有可插入数据库
alter session set container=orclpdb;
create user scott identified by tiger;
grant connect,resource,unlimited tablespace to scott;
alter user scott default tablespace users;
alter user scott temporary tablespace temp;
sqlplus scott/tiger@localhost:1521/orclpdb
