orcle经常使用语句

--1.创建暂时表空间
create temporary tablespace AUTOMONITORV5_temp
tempfile 'D:\ORACLE\KARL\ORADATA\ORCL\AUTOMONITORV5_temp.DBF'  
size 50m    
autoextend on   
next 50m maxsize 10240m   
extent management local; 

--2.创建表空间
create tablespace AUTOMONITORV5   
logging   
datafile 'D:\ORACLE\KARL\ORADATA\ORCL\AUTOMONITORV5.DBF'  
size 50m   
autoextend on   
next 50m maxsize 12720m   
extent management local;  

--3.创建用户
create user automonitorv5 identified by "123456"   
default tablespace AUTOMONITORV5   
temporary tablespace AUTOMONITORV5_temp;  

--4.授权
grant connect,resource,dba to automonitorv5; 

--5.删除用户
drop user automonitorv5 cascade;

--6.删除表空间
DROP TABLESPACE automonitorv5 INCLUDING CONTENTS AND DATAFILES;

--7.查询表空间位置及大小
select tablespace_name,
       file_id,
       file_name,
       round(bytes / (1024 * 1024), 0) total_space
  from dba_data_files
 order by tablespace_name;
 
--8.表空间使用率
SELECT a.tablespace_name "表空间名",
       total "表空间大小",
       free "表空间剩余大小",
       (total - free) "表空间使用大小",
       Round((total - free) / total, 4) * 100 "使用率   %"
  FROM (SELECT tablespace_name, Sum(bytes) free
          FROM DBA_FREE_SPACE
         GROUP BY tablespace_name) a,
       (SELECT tablespace_name, Sum(bytes) total
          FROM DBA_DATA_FILES
         GROUP BY tablespace_name) b
 WHERE a.tablespace_name = b.tablespace_name;
 
--9.增大表空间大小
alter database datafile 'D:\ORACLE\KARL\ORADATA\ORCL\AUTOMONITORV5.DBF' resize 4000m;

--10.添加文件个数
alter tablespace AUTOMONITORV5
     add datafile 'D:\ORACLE\KARL\ORADATA\ORCL\AUTOMONITORV51.DBF' size 1000m;
     
--11.设置表空间自己主动增长
alter database datafile 'D:\ORACLE\KARL\ORADATA\ORCL\AUTOMONITORV5.DBF'
      autoextend on next 100m maxsize 10240m;

--12.获取10年前的日期
select to_char(sysdate-numtoyminterval(10,'year'),'yyyy-MM-dd HH24:mi:ss') from dual;

--13.小数转字符补零方法
1)将小数点前的第一位置为0就可以(注意9的个数要大于数值的位数)
select to_char(.23,'fm999999990.999999999') from dual;
2)既然小于1的小数首位必定是'.'，那就推断首位是否为'.'。是则在前面加上'0'就可以
select decode(substr(.23,1,1),'.','0'||.23,.23) from dual; 
<a target=_blank href="http://www.2cto.com/database/201304/205087.html">oracle小数转字符串</a>