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_USERS8.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 CASCADE11、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 1000000BEGINfor c in ( select ‘ALTER TABLE ‘ ||TABLE_NAME|| ‘ ENABLE CONSTRAINT ‘ ||constraint_name|| ‘ ‘ as v_sql from user_constraintswhere CONSTRAINT_TYPE= ‘R‘ ) loopDBMS_OUTPUT.PUT_LINE(C.V_SQL);beginEXECUTE 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 1000000BEGINfor c in ( select ‘ALTER TABLE ‘ ||TABLE_NAME|| ‘ DISABLE CONSTRAINT ‘ ||constraint_name|| ‘ ‘ as v_sql from user_constraintswhere CONSTRAINT_TYPE= ‘R‘ ) loopDBMS_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 ;原文：https://www.cnblogs.com/lma0702/p/14018656.html