1.查看所有用户：
select * from dba_users;
select * from all_users;
select * from user_users;
2.查看用户或角色系统权限(直接赋值给用户或角色的系统权限)：
select * from dba_sys_privs;
select * from user_sys_privs; (查看当前用户所拥有的权限)
3.查看角色(只能查看登陆用户拥有的角色)所包含的权限
sql>select * from role_sys_privs;
4.查看用户对象权限：
select * from dba_tab_privs;
select * from all_tab_privs;
select * from user_tab_privs;
5.查看所有角色：
select * from dba_roles;
6.查看用户或角色所拥有的角色：
select * from dba_role_privs;
select * from user_role_privs;
7.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
8.SqlPlus中查看一个用户所拥有权限
SQL>select * from dba_sys_privs where grantee=\'username\';
其中的username即用户名要大写才行。
比如：
SQL>select * from dba_sys_privs where grantee=\'TOM\';
9、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)\';
10、删除用户
drop user user_name cascade;
如：drop user SMCHANNEL CASCADE
11、获取当前用户下所有的表：select table_name from user_tables;
12、删除某用户下所有的表数据: select \'truncate table \' || table_name from user_tables;
13、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\'表示是外键约束。
启用外键约束的命令为：alter table table_name enable constraint constraint_name
禁用外键约束的命令为：alter table table_name disable constraint constraint_name
然后再用SQL查出数据库中所以外键的约束名：
select \'alter table \'||table_name||\' enable constraint \'||constraint_name||\';\' from user_constraints where constraint_type=\'R\'
select \'alter table \'||table_name||\' disable constraint \'||constraint_name||\';\' from user_constraints where constraint_type=\'R\'
14、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;