INTERVAL 用法 mysql

原文:https://blog.csdn.net/sqlquan/article/details/82699237

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+ interval '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

时间间隔字面量

说明

INTERVAL ‘3’ DAY

时间间隔为3天

INTERVAL ‘2’ HOUR

时间间隔为2小时

INTERVAL ‘25’ MINUTE

时间间隔为25分钟

INTERVAL ‘45’ SECOND

时间间隔为45秒

INTERVAL ‘3 2’ DAY TO HOUR

时间间隔为3天零2小时

INTERVAL ‘3 2:25’ DAY TO MINUTE

时间间隔为3天零2小时25分

INTERVAL ‘3 2:25:45’ DAY TO SECOND

时间间隔为3天零2小时25分45秒

INTERVAL ‘123 2:25:45.12’ DAY(3)

TO SECOND(2)

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

INTERVAL ‘3 2:00:45’ DAY TO SECOND

时间间隔为3天2小时0分45秒

INTERVAL ‘-3 2:25:45’ DAY TO SECOND

时间间隔为负数,值为3天零2小时25分45秒

INTERVAL ‘1234 2:25:45’ DAY(3)

TO SECOND

时间间隔无效,因为天的位数超过了指定的精度3

INTERVAL ‘123 2:25:45.123’ DAY

TO SECOND(2)

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

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

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