1、备份单张表
   创建复制表结构
   create table  employeesbak as select * from cims.employees
   如果只复制表结构，只需要在结尾加上   where 1=0
   插入数据
   insert into employeesbak
   select * from   cims.employees
  删除一条数据
  delete  from  jjl_customersource jc  where  jc.code='C0000151721' and jc.name='唐';

  select   * from   jjl_customersource j  where j.code='C0000151721';

2、Sql代码  
--查看所有的用户  
select * from all_users;  
--查看当前用户信息  
select * from user_users;  
--查看当前用户的角色  
select * from user_role_privs;  
--查看当前用户的权限  
select * from user_sys_privs;  
--查看当前用户的表可操作权限  
select * from user_tab_privs; 

3、获取星期几
select to_char(sysdate,'day') dayth from dual

5、查看所有被锁的表
select b.owner TABLEOWNER, b.object_name TABLENAME, c.OSUSER LOCKBY,
c.USERNAME LOGINID, c.sid SID, c.SERIAL# SERIAL
from v$locked_object a,dba_objects b, v$session c 
where b.object_id = a.object_id AND a.SESSION_ID =c.sid;

6、解锁表
alter system kill session 'SID, SERIAL';

7、查看表空间的使用情况
SELECT a.tablespace_name, 
a.bytes total, 
b.bytes used, 
c.bytes free, 
(b.bytes * 100) / a.bytes "% USED ", 
(c.bytes * 100) / a.bytes "% FREE " 
FROM sys.sm$ts_avail a, sys.sm$ts_used b, sys.sm$ts_free c 
WHERE a.tablespace_name = b.tablespace_name 
AND a.tablespace_name = c.tablespace_name; 

8、查看表空间的路径
select tablespace_name, file_id, file_name,
round(bytes/(1024*1024),0) total_space
from dba_data_files where tablespace_name='SYSAUX'
order by file_name;

9、添加数据文件

alter tablespace SYSAUX add datafile '+DATA01/wyzx/datafile/sysaux_20210430' size 10 G;

给表空间SYSAUX添加10G的数据文件

10、删掉重复项
找出主键为nrcelldu_uk，start_time都重复的数据，只留下一条数据

delete from pm.F_5_C_S_NRCELLDU_PRB_Q a 
where (a.nrcelldu_uk,a.start_time) in 
(select nrcelldu_uk,start_time from pm.F_5_C_S_NRCELLDU_PRB_Q 
group by nrcelldu_uk,start_time having count(*) > 1) 
and rowid not in (select max(rowid) 
from pm.F_5_C_S_NRCELLDU_PRB_Q group by nrcelldu_uk,start_time having count(*)>1
);
commit;

11、查看归档日志
SELECT A.NAME, A.TOTAL_MB / 1024, A.FREE_MB / 1024 FROM V$ASM_DISKGROUP A