INTERVAL 用法 mysql

港控/mmm° 2022-05-12 04:00 186阅读 0赞

做个例子描述吧，也许更易于理解。

准备：

1.建表

create table INTERVAL\_TEST  
(  
  t\_id     INTEGER not null,  --纯id  
  t\_date   VARCHAR2(40) not null,--时间，如果此处类型为date最好，不过现在很多应用都喜欢把时间建成varchar2  
  t\_flagCHAR(40)  --没什么业务含义，只是个标记  
)

2.造数据

001        2011-01-01 12:00:00        1                                         
001        2011-01-02 12:00:00        1                                         
001        2011-01-03 12:00:00        1                                         
002        2011-01-01 12:00:00        1                                         
002        2011-01-03 12:00:00        1                                         
002        2011-01-05 12:00:00        1

3.写SQL：同一ID，如果时间连续两天flag为1，则把第二天...第N天的flag修改为0。

update interval\_test  
   set interval\_test.flag= '0'  
 where exists  
 (select \*  
          from interval\_test i  
         where interval\_test.t\_id = i.t\_id  
           and to\_date(interval\_test.t\_date, 'yyyy-mm-dd hh24:mi:ss') =  
               to\_date(i.t\_date, 'yyyy-mm-dd hh24:mi:ss') +** interval '1' day**)

\--因为建表时时间字段为varchar2，所以这里需要to\_date一下。

commit后，查询结果：

1 2011-01-01 12:00:00 1                                         
1 2011-01-02 12:00:00 0                                         
1 2011-01-03 12:00:00 0                                         
2 2011-01-01 12:00:00 1                                         
2 2011-01-03 12:00:00 1                                         
2 2011-01-05 12:00:00 1

结论，interval为取间隔的含义，在这个SQL中，子查询的where条件中红色部分含义说白了就是：当A表时间 = B表时间 + 1天

也可以扩展使用为间隔多少小时：A.T\_DATE = B.T\_DATE+ i**nterval '1' hour——**即 A表时间 = B表时间 + 1小时，也可以为分钟、秒。

Oracle里有INTERVAL DAY TO SECOND类型，在建表时可以定义，只提供下表作为释义。

具体类型的使用方式参考：[http://book.51cto.com/art/200812/103848.htm][http_book.51cto.com_art_200812_103848.htm]

<table> 
 <tbody> 
 <tr> 
 <td style="vertical-align:top;"> 时间间隔字面量 </td> 
 <td style="vertical-align:top;"> 说明 </td> 
 </tr> 
 <tr> 
 <td style="vertical-align:top;"> INTERVAL ‘3’ DAY </td> 
 <td style="vertical-align:top;"> 时间间隔为3天 </td> 
 </tr> 
 <tr> 
 <td style="vertical-align:top;"> INTERVAL ‘2’ HOUR </td> 
 <td style="vertical-align:top;"> 时间间隔为2小时 </td> 
 </tr> 
 <tr> 
 <td style="vertical-align:top;"> INTERVAL ‘25’ MINUTE </td> 
 <td style="vertical-align:top;"> 时间间隔为25分钟 </td> 
 </tr> 
 <tr> 
 <td style="vertical-align:top;"> INTERVAL ‘45’ SECOND </td> 
 <td style="vertical-align:top;"> 时间间隔为45秒 </td> 
 </tr> 
 <tr> 
 <td style="vertical-align:top;"> INTERVAL ‘3 2’ DAY TO HOUR </td> 
 <td style="vertical-align:top;"> 时间间隔为3天零2小时 </td> 
 </tr> 
 <tr> 
 <td style="vertical-align:top;"> INTERVAL ‘3 2:25’ DAY TO MINUTE </td> 
 <td style="vertical-align:top;"> 时间间隔为3天零2小时25分 </td> 
 </tr> 
 <tr> 
 <td style="vertical-align:top;"> INTERVAL ‘3 2:25:45’ DAY TO SECOND </td> 
 <td style="vertical-align:top;"> 时间间隔为3天零2小时25分45秒 </td> 
 </tr> 
 <tr> 
 <td style="vertical-align:top;"> INTERVAL ‘123 2:25:45.12’ DAY(3) TO SECOND(2) </td> 
 <td style="vertical-align:top;"> 时间间隔为123天零2小时25分45.12秒； 天的精度是3位数字，秒的小数部分的精度是2位数字 </td> 
 </tr> 
 <tr> 
 <td style="vertical-align:top;"> INTERVAL ‘3 2:00:45’ DAY TO SECOND </td> 
 <td style="vertical-align:top;"> 时间间隔为3天2小时0分45秒 </td> 
 </tr> 
 <tr> 
 <td style="vertical-align:top;"> INTERVAL ‘-3 2:25:45’ DAY TO SECOND </td> 
 <td style="vertical-align:top;"> 时间间隔为负数，值为3天零2小时25分45秒 </td> 
 </tr> 
 <tr> 
 <td style="vertical-align:top;"> INTERVAL ‘1234 2:25:45’ DAY(3) TO SECOND </td> 
 <td style="vertical-align:top;"> 时间间隔无效，因为天的位数超过了指定的精度3 </td> 
 </tr> 
 <tr> 
 <td style="vertical-align:top;"> INTERVAL ‘123 2:25:45.123’ DAY TO SECOND(2) </td> 
 <td style="vertical-align:top;"> 时间间隔无效，因为秒的小数部分的位数超过了指定的精度2 </td> 
 </tr> 
 </tbody> 
</table>

**INTERVAL YEAR TO MONTH数据类型**  
 
Oracle语法:  
INTERVAL 'integer \[- integer\]' \{YEAR | MONTH\} \[(precision)\]\[TO \{YEAR | MONTH\}\]  
 
该数据类型常用来表示一段时间差, 注意时间差只精确到年和月. precision为年或月的精确域, 有效范围是0到9, 默认值为2.  
 
eg:  
INTERVAL '123-2' YEAR(3) TO MONTH      
表示: 123年2个月, "YEAR(3)" 表示年的精度为3, 可见"123"刚好为3为有效数值, 如果该处YEAR(n), n<3就会出错, 注意默认是2.  
 
INTERVAL '123' YEAR(3)  
表示: 123年0个月  
 
INTERVAL '300' MONTH(3)  
表示: 300个月, 注意该处MONTH的精度是3啊.  
 
INTERVAL '4' YEAR      
表示: 4年, 同 INTERVAL '4-0' YEAR TO MONTH 是一样的  
 
INTERVAL '50' MONTH      
表示: 50个月, 同 INTERVAL '4-2' YEAR TO MONTH 是一样  
 
INTERVAL '123' YEAR      
表示: 该处表示有错误, 123精度是3了, 但系统默认是2, 所以该处应该写成 INTERVAL '123' YEAR(3) 或"3"改成大于3小于等于9的数值都可以的  
 
INTERVAL '5-3' YEAR TO MONTH + INTERVAL '20' MONTH =  
INTERVAL '6-11' YEAR TO MONTH  
表示: 5年3个月 + 20个月 = 6年11个月  
 
与该类型相关的函数:  
NUMTODSINTERVAL(n, 'interval\_unit')  
将n转换成interval\_unit所指定的值, interval\_unit可以为: DAY, HOUR, MINUTE, SECOND  
注意该函数不可以转换成YEAR和MONTH的.  
 
NUMTOYMINTERVAL(n, 'interval\_unit')  
interval\_unit可以为: YEAR, MONTH  
 
eg: (Oracle Version 9204, RedHat Linux 9.0)  
SQL> select numtodsinterval(100,'DAY') from dual;  
 
NUMTODSINTERVAL(100,'DAY')                                                       
\---------------------------------------------------------------------------      
\+000000100 00:00:00.000000000                                                    
 
SQL> c/DAY/SECOND  
  1\* select numtodsinterval(100,'SECOND') from dual  
SQL> /  
 
NUMTODSINTERVAL(100,'SECOND')                                                    
\---------------------------------------------------------------------------      
\+000000000 00:01:40.000000000                                                    
 
SQL> c/SECOND/MINUTE  
  1\* select numtodsinterval(100,'MINUTE') from dual  
SQL> /  
 
NUMTODSINTERVAL(100,'MINUTE')                                                    
\---------------------------------------------------------------------------      
\+000000000 01:40:00.000000000                                                    
 
SQL> c/MINUTE/HOUR  
  1\* select numtodsinterval(100,'HOUR') from dual  
SQL> /  
 
NUMTODSINTERVAL(100,'HOUR')                                                      
\---------------------------------------------------------------------------      
\+000000004 04:00:00.000000000                                                    
 
SQL> c/HOUR/YEAR  
  1\* select numtodsinterval(100,'YEAR') from dual  
SQL> /  
select numtodsinterval(100,'YEAR') from dual  
                           \*  
ERROR at line 1:  
ORA-01760: illegal argument for function  
 
SQL> select numtoyminterval(100,'year') from dual;  
 
NUMTOYMINTERVAL(100,'YEAR')                                                      
\---------------------------------------------------------------------------      
\+000000100-00                                                                    
 
SQL> c/year/month  
  1\* select numtoyminterval(100,'month') from dual  
SQL> /  
 
NUMTOYMINTERVAL(100,'MONTH')                                                     
\---------------------------------------------------------------------------      
\+000000008-04                                                                    
 
 
时间的计算:  
SQL> select to\_date('1999-12-12','yyyy-mm-dd') - to\_date('1999-12-01','yyyy-mm-dd') from dual;  
 
TO\_DATE('1999-12-12','YYYY-MM-DD')-TO\_DATE('1999-12-01','YYYY-MM-DD')            
\---------------------------------------------------------------------            
                                                                   11            
\-- 可以相减的结果为天.  
 
SQL> c/1999-12-12/1999-01-12  
  1\* select to\_date('1999-01-12','yyyy-mm-dd') - to\_date('1999-12-01','yyyy-mm-dd') from dual  
SQL> /  
 
TO\_DATE('1999-01-12','YYYY-MM-DD')-TO\_DATE('1999-12-01','YYYY-MM-DD')            
\---------------------------------------------------------------------            
                                                                 -323            
\-- 也可以为负数的  
 
SQL> c/1999-01-12/2999-10-12  
  1\* select to\_date('2999-10-12','yyyy-mm-dd') - to\_date('1999-12-01','yyyy-mm-dd') from dual  
SQL> /  
 
TO\_DATE('2999-10-12','YYYY-MM-DD')-TO\_DATE('1999-12-01','YYYY-MM-DD')            
\---------------------------------------------------------------------            
                                                               365193            
 
下面看看INTERVAL YEAR TO MONTH怎么用.  
SQL> create table bb(a date, b date, c interval year(9) to month);  
 
Table created.  
 
SQL> desc bb;  
Name                                      Null?    Type  
\----------------------------------------- -------- ----------------------------  
A                                                  DATE  
B                                                  DATE  
C                                                  INTERVAL YEAR(9) TO MONTH  
 
SQL> insert into bb values(to\_date('1985-12-12', 'yyyy-mm-dd'), to\_date('1984-12-01','yyyy-mm-dd'), null)  
 
1 row created.  
 
SQL> select \* from bb;  
 
A         B                                                                      
\--------- ---------                                                              
C                                                                                
\---------------------------------------------------------------------------      
12-DEC-85 01-DEC-84                                                              
                                                                                 
                                                                                 
SQL> update bb set c = numtoyminterval(a-b, 'year');  
 
1 row updated.  
 
SQL> select \* from bb;  
 
A         B                                                                      
\--------- ---------                                                              
C                                                                                
\---------------------------------------------------------------------------      
12-DEC-85 01-DEC-84                                                              
\+000000376-00                                                                    
                                                                                 
\-- 直接将相减的天变成年了, 因为我指定变成年的  
SQL> select a-b, c from bb;  
 
       A-B                                                                       
\----------                                                                       
C                                                                                
\---------------------------------------------------------------------------      
       376                                                                       
\+000000376-00                                                                    
                                                                                 
 
SQL> insert into bb values(null,null,numtoyminterval(376,'month'));  
 
1 row created.  
 
SQL> select \* from bb;  
 
A         B             C                                                         
\--------- ---------    --------------------------------------------      
12-DEC-85 01-DEC-84    +000000376-00                                                                    
                         +000000031-04                                           
 
SQL> insert into bb values ( null,null, numtoyminterval(999999999,'year'));  
 
1 row created.  
 
SQL> select \* from bb;  
 
A           B            C                                  
\---------   ---------     ---------------------------------------------------------------------      
12-DEC-85   01-DEC-84   +000000376-00                                                                    
                          +000000031-04  
                          +999999999-00                                                                  
 
========================  
今天来添加点新的东西！\[2008-07-26\] 这部分东东来源：http://www.oraclefans.cn/forum/showblog.jsp?rootid=139  
 
INTERVAL YEAR TO MONTH类型2个TIMESTAMP类型的时间差别。内部类型是182，长度是5。其中4个字节存储年份差异，存储的时候在差异上加了一个0X80000000的偏移量。一个字节存储月份的差异，这个差异加了60的偏移量。  
 
SQL> ALTER TABLE TestTimeStamp ADD E INTERVAL YEAR TO MONTH;  
SQL> update testTimeStamp set e=(select interval '5' year + interval '10' month year  from dual);  
 
已更新3行。  
 
SQL> commit;  
提交完成。  
 
SQL> select dump(e,16) from testTimeStamp;  
 
DUMP(E,16)  
\---------------------------------------------  
Typ=182 Len=5: 80,0,0,5,46  
Typ=182 Len=5: 80,0,0,5,46  
Typ=182 Len=5: 80,0,0,5,46  
 
年：0X80000005-0X80000000=5  
月：0x46-60=10  
 
**INTERVAL DAY TO SECOND数据类型**  
 
Oracle语法:  
INTERVAL '\{ integer | integer time\_expr | time\_expr \}'  
\{ \{ DAY | HOUR | MINUTE \} \[ ( leading\_precision ) \]  
| SECOND \[ ( leading\_precision \[, fractional\_seconds\_precision \] ) \] \}  
\[ TO \{ DAY | HOUR | MINUTE | SECOND \[ (fractional\_seconds\_precision) \] \} \]  
 
leading\_precision值的范围是0到9, 默认是2. time\_expr的格式为:HH\[:MI\[:SS\[.n\]\]\] or MI\[:SS\[.n\]\] or SS\[.n\], n表示微秒.  
该类型与INTERVAL YEAR TO MONTH有很多相似的地方,建议先看INTERVAL YEAR TO MONTH再看该文.  
 
范围值:  
HOUR:    0 to 23  
MINUTE: 0 to 59  
SECOND: 0 to 59.999999999  
 
eg:  
INTERVAL '4 5:12:10.222' DAY TO SECOND(3)  
表示: 4天5小时12分10.222秒  
 
INTERVAL '4 5:12' DAY TO MINUTE  
表示: 4天5小时12分  
 
INTERVAL '400 5' DAY(3) TO HOUR  
表示: 400天5小时, 400为3为精度,所以"DAY(3)", 注意默认值为2.  
 
INTERVAL '400' DAY(3)  
表示: 400天  
 
INTERVAL '11:12:10.2222222' HOUR TO SECOND(7)  
表示: 11小时12分10.2222222秒  
 
INTERVAL '11:20' HOUR TO MINUTE  
表示: 11小时20分  
 
INTERVAL '10' HOUR  
表示: 10小时  
 
INTERVAL '10:22' MINUTE TO SECOND  
表示: 10分22秒  
 
INTERVAL '10' MINUTE  
表示: 10分  
 
INTERVAL '4' DAY  
表示: 4天  
 
INTERVAL '25' HOUR  
表示: 25小时  
 
INTERVAL '40' MINUTE  
表示: 40分  
 
INTERVAL '120' HOUR(3)  
表示: 120小时  
 
INTERVAL '30.12345' SECOND(2,4)      
表示: 30.1235秒, 因为该地方秒的后面精度设置为4, 要进行四舍五入.  
 
INTERVAL '20' DAY - INTERVAL '240' HOUR = INTERVAL '10-0' DAY TO SECOND  
表示: 20天 - 240小时 = 10天0秒  
 
==================  
该部分来源：http://www.oraclefans.cn/forum/showblog.jsp?rootid=140  
INTERVAL DAY TO SECOND类型存储两个TIMESTAMP之间的时间差异，用日期、小时、分钟、秒钟形式表示。该数据类型的内部代码是183，长度位11字节：  
 
l         4个字节表示天数（增加0X80000000偏移量）  
l         小时、分钟、秒钟各用一个字节表示（增加60偏移量）  
l         4个字节表示秒钟的小时差异（增加0X80000000偏移量）  
 
以下是一个例子：  
 
SQL> alter table testTimeStamp add f interval day to second ;  
 
表已更改。  
 
SQL> update testTimeStamp set f=(select interval '5' day + interval '10' second from dual);  
 
已更新3行。  
 
SQL> commit;  
 
提交完成。  
 
SQL> select dump(f,16) from testTimeStamp;  
 
DUMP(F,16)  
 
\--------------------------------------------------------------------------------  
 
Typ=183 Len=11: 80,0,0,5,3c,3c,46,80,0,0,0  
Typ=183 Len=11: 80,0,0,5,3c,3c,46,80,0,0,0  
Typ=183 Len=11: 80,0,0,5,3c,3c,46,80,0,0,0  
 
日期：0X80000005-0X80000000=5  
 
小时：60－60＝0  
分钟：60－60＝0  
秒钟：70－60＝10  
秒钟小数部分：0X80000000-0X80000000=0

[http_book.51cto.com_art_200812_103848.htm]: http://book.51cto.com/art/200812/103848.htm