在测试环境做数据处理时，发现表的连接有问题，以下是简单的模拟了一下。
--drop表后，role中赋予的权限会自动回收
SQL> create user hrc identified by hrc;
SQL> create user hrc identified by hrc;
User created.
SQL> grant connect,resource to hrc;
SQL> grant connect,resource to hrc;
Grant succeeded.
SQL> conn hr/hr
SQL> create role hr_all;
Role created.
SQL> grant select,insert,update,delete on tt to hr_all;
Grant succeeded.
SQL> grant hr_all to hrc;
Grant succeeded.
SQL> /
select count(*) from hr.tt
*
ERROR at line 1:
ORA-00942: table or view does not exist --需要建同义词之类的
select count(*) from hr.tt
*
ERROR at line 1:
ORA-00942: table or view does not exist --需要建同义词之类的
SQL> select count(*) from hr.tt;
COUNT(*)
----------
4162
----------
4162
SQL> conn hr/hr
SQL> drop table tt;
Table dropped.
--使用hrc来查询，会报错
SQL> select count(*) from hr.tt;
select count(*) from hr.tt
*
ERROR at line 1:
ORA-00942: table or view does not exist
SQL> select count(*) from hr.tt;
select count(*) from hr.tt
*
ERROR at line 1:
ORA-00942: table or view does not exist
--hr 重建表tt
SQL> create table tt as select * from all_objects where rownum
SQL> create table tt as select * from all_objects where rownum
Table created.
--使用hrc来查询，还是会报错
SQL> select count(*) from hr.tt;
select count(*) from hr.tt
*
ERROR at line 1:
ORA-00942: table or view does not exist
SQL> select count(*) from hr.tt;
select count(*) from hr.tt
*
ERROR at line 1:
ORA-00942: table or view does not exist
drop后需要重新赋权限。
