MySQL時間差返回月個數

select PERIOD_DIFF(date_format(now(),'%Y%m'),date_format('2010-11-30','%Y%m'))

1. MySQL 為日期增加一個時間間隔：date_add() 

set @dt = now();
select date_add(@dt, interval 1 day); -- add 1 day
select date_add(@dt, interval 1 hour); -- add 1 hour
select date_add(@dt, interval 1 minute); -- ...
select date_add(@dt, interval 1 second);
select date_add(@dt, interval 1 microsecond);
select date_add(@dt, interval 1 week);
select date_add(@dt, interval 1 month);
select date_add(@dt, interval 1 quarter);
select date_add(@dt, interval 1 year);
select date_add(@dt, interval -1 day); -- sub 1 day

MySQL adddate(), addtime()函數，可以用 date_add() 來替代。下面是 date_add() 實現 addtime() 功能示例： 

mysql> set @dt = '2008-08-09 12:12:33';
mysql>
mysql> select date_add(@dt, interval '01:15:30' hour_second);
+------------------------------------------------+
| date_add(@dt, interval '01:15:30' hour_second) |
+------------------------------------------------+
| 2008-08-09 13:28:03 |
+------------------------------------------------+
mysql> select date_add(@dt, interval '1 01:15:30' day_second);
+-------------------------------------------------+
| date_add(@dt, interval '1 01:15:30' day_second) |
+-------------------------------------------------+
| 2008-08-10 13:28:03 |
+-------------------------------------------------+

date_add() 函數，分別為 @dt 增加了“1小時 15分 30秒” 和 “1天 1小時 15分 30秒”。建議：總是使用 date_add() 日期時間函數來替代 adddate(), addtime()。 

　　2. MySQL 為日期減去一個時間間隔：date_sub() 

mysql> select date_sub('1998-01-01 00:00:00', interval '1 1:1:1' day_second);

+----------------------------------------------------------------+
| date_sub('1998-01-01 00:00:00', interval '1 1:1:1' day_second) |
+----------------------------------------------------------------+
| 1997-12-30 22:58:59 |
+----------------------------------------------------------------+

MySQL date_sub() 日期時間函數 和 date_add() 用法一致，不再贅述。另外，MySQL 中還有兩個函數 subdate(), subtime()，建議，用 date_sub() 來替代。 

　　3. MySQL 另類日期函數：period_add(P,N), period_diff(P1,P2) 
　　函數參數“P” 的格式為“YYYYMM” 或者 “YYMM”，第二個參數“N” 表示增加或減去 N month（月）。 
MySQL period_add(P,N)：日期加/減去N月。 

mysql> select period_add(200808,2), period_add(20080808,-2)
+----------------------+-------------------------+
| period_add(200808,2) | period_add(20080808,-2) |
+----------------------+-------------------------+
| 200810 | 20080806 |
+----------------------+-------------------------+

MySQL period_diff(P1,P2)：日期 P1-P2，返回 N 個月。 

mysql> select period_diff(200808, 200801);
+-----------------------------+
| period_diff(200808, 200801) |
+-----------------------------+
| 7 |
+-----------------------------+

在 MySQL 中，這兩個日期函數，一般情況下很少用到。 

4. MySQL 日期、時間相減函數：datediff(date1,date2), timediff(time1,time2) 
MySQL datediff(date1,date2)：兩個日期相減 date1 - date2，返回天數。 

select datediff('2008-08-08', '2008-08-01'); -- 7
select datediff('2008-08-01', '2008-08-08'); -- -7

MySQL timediff(time1,time2)：兩個日期相減 time1 - time2，返回 time 差值。 

select timediff('2008-08-08 08:08:08', '2008-08-08 00:00:00'); -- 08:08:08
select timediff('08:08:08', '00:00:00'); -- 08:08:08

注意：timediff(time1,time2) 函數的兩個參數類型必須相同。 

MySQL查詢的方式很多，下面為您介紹的MySQL查詢實現的是查詢本周、上周、本月、上個月份的數據，如果您對MySQL查詢方面感興趣的話，不妨一看。 

查詢當前這周的數據 

SELECT name,submittime FROM enterprise WHERE YEARWEEK(date_format(submittime,'%Y-%m-%d')) = YEARWEEK(now());

查詢上周的數據 

SELECT name,submittime FROM enterprise WHERE YEARWEEK(date_format(submittime,'%Y-%m-%d')) = YEARWEEK(now())-1;

查詢當前月份的數據 

select name,submittime from enterprise   where date_format(submittime,'%Y-%m')=date_format(now(),'%Y-%m')

查詢距離當前現在6個月的數據 

select name,submittime from enterprise where submittime between date_sub(now(),interval 6 month) and now();

查詢上個月的數據 

select name,submittime from enterprise   where date_format(submittime,'%Y-%m')=date_format(DATE_SUB(curdate(), INTERVAL 1 MONTH),'%Y-%m')

select * from `user` where DATE_FORMAT(pudate,'%Y%m') = DATE_FORMAT(CURDATE(),'%Y%m') ;

select * from user where WEEKOFYEAR(FROM_UNIXTIME(pudate,'%y-%m-%d')) = WEEKOFYEAR(now())

select *
from user
where MONTH(FROM_UNIXTIME(pudate,'%y-%m-%d')) = MONTH(now())

select *
from [user]
where YEAR(FROM_UNIXTIME(pudate,'%y-%m-%d')) = YEAR(now())
and MONTH(FROM_UNIXTIME(pudate,'%y-%m-%d')) = MONTH(now())

select *
from [user]
where pudate between 上月最后一天
and 下月第一天