ORACLE学习汇总

1.查看所有用户

select * from all_users;

select * from dba_users;

select * from user_users;

2.查看用户或角色系统权限

select * from user_sys_privs;(当前用户的权限)

select * from role_sys_privs;（登陆用户所拥有的角色）

select * from dba_sys_privs;

3.查看所有角色
select * from dba_roles;

4.查看用户对象权限

select * from all_tab_privs;

select * from dba_tab_privs;

select * from user_tab_privs;

5.查看用户或角色所拥有的角色

select * from dba_role_privs;

select * from user_role_privs;

6.查看哪些用户有sysdba或sysoper系统权限(查询时需要相应权限)

select * from V$PWFILE_USERS

注意：用sqlplus登陆sys用户的时候，用户名应该输入：sys as sysdba，否则会报错！

在sql deverloper中新建一个sys的连接也是一样的，用户名要写为：sys as sysdba。

7.sqlplus中查看一个用户所拥有权限

SQL> select * from dba_sys_privs where grantee='username';(username即用户名要大写才行)

8.oracle删除指定用户所有表的方法
select 'drop table' ||table_name|| ';' from all_tables where owner='要删除的用户名（注意要大写）';

9.删除用户

drop user user_nsme cascade;

10.查看当前用户下所有的表

select table_name from user_tables;

11.删除某用户下所有的表数据

select 'truncate table' || table_name from user_tables;

12.禁止外键ORACLE数据库中的外键约束名都在表user_constraints中可以查到

其中constraint_type='R'标识是外键约束

启用外键约束的命令为：altre table table_name enable constraint constraint_name

禁用外键约束的命令为：alter tabel table_name disable constraint constraint_name

然后再用SQL查出数据库中所有外键的约束名：

select 'altre table' ||table_name|| 'enable constraint' ||constraint_name|| ';' from user_constraints where constraint_type='R'

select 'altre table' ||table_name|| 'disable constraint' ||constraint_name|| ';' from user_constraints where constraint_type='R'

13.ORACLE禁用/启用外键和触发器 --启用脚本
SET SERVEROUTPUT ON SIZE 1000000
BEGIN
for c in (select 'ALTER TABLE '||TABLE_NAME||' ENABLE CONSTRAINT '||constraint_name||' ' as v_sql from user_constraints
where CONSTRAINT_TYPE='R') loop
DBMS_OUTPUT.PUT_LINE(C.V_SQL);
begin
EXECUTE IMMEDIATE c.v_sql;
exception when others then
dbms_output.put_line(sqlerrm);
end;
end loop;
for c in (select 'ALTER TABLE '||TNAME||' ENABLE ALL TRIGGERS ' AS v_sql from tab where tabtype='TABLE') loop
dbms_output.put_line(c.v_sql);
begin
execute immediate c.v_sql;
exception when others then
dbms_output.put_line(sqlerrm);
end;
end loop;
end;
/
commit;

--禁用脚本
SET SERVEROUTPUT ON SIZE 1000000
BEGIN
for c in (select 'ALTER TABLE '||TABLE_NAME||' DISABLE CONSTRAINT '||constraint_name||' ' as v_sql from user_constraints
where CONSTRAINT_TYPE='R') loop
DBMS_OUTPUT.PUT_LINE(C.V_SQL);
begin
EXECUTE IMMEDIATE c.v_sql;
exception when others then
dbms_output.put_line(sqlerrm);
end;
end loop;
for c in (select 'ALTER TABLE '||TNAME||' DISABLE ALL TRIGGERS ' AS v_sql from tab where tabtype='TABLE') loop
dbms_output.put_line(c.v_sql);
begin
execute immediate c.v_sql;
exception when others then
dbms_output.put_line(sqlerrm);
end;
end loop;
end;
/
commit;