查询、删除Oracle中用户信息

查询Oracle中所有用户信息，删除用户、表，禁止外键等。 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;