Question

假设我有

     > ID               FromDate                         ToDate 
     > --              --------                         -------
     > 1               '2013-12-14 00:00:00'         '2013-12-23 00:00:00'
     > 2               '2013-12-24 00:00:00'         '2013-12-31 00:00:00'

对于我的场景，用户从'2013-12-14 00:00:00'搜索到'2013-12-29 00:00:00'

总天数为“15”。我想输出像这样的东西

 > ID                  FromDate                         ToDate                countdays
 > --              --------                         -------
 > 1               '2013-12-14 00:00:00'         '2013-12-23 00:00:00'         9
 > 2               '2013-12-24 00:00:00'         '2013-12-31 00:00:00'         6

9 + 6 = 15

第一行fromdate和todate介于用户fromdate和todate之间，因此countdays为9 第二行我想要从'2013-12-24 00:00:00'到'2013-12-29 00:00:00'计算天数我怎么能用mysql做这个？

Answer 1

<强> SQL 选择ID，FromDate，ToDate，DATEDIFF（DAY，ToDate，FromDate）作为TableName的计数

SQL中的语法：

DATEDIFF（日期部分，开始日期，结束日期）

<强> MYSQL

Select ID, FromDate, ToDate , DATEDIFF(ToDate, FromDate) As Count From TableName

示例：

DATEDIFF(expr1,expr2) DATEDIFF() returns expr1 – expr2 expressed as a value in days from one date to the other. expr1 and expr2 are date or date-and-time expressions. Only the date parts of the values are used in the calculation. mysql> SELECT DATEDIFF('2007-12-31 23:59:59','2007-12-30'); -> 1 mysql> SELECT DATEDIFF('2010-11-30 23:59:59','2010-12-31'); -> -31

来源：Date Difference documentation by MYSQL

希望这有帮助

Answer 2

你可以这样试试

SELECT t.*, 
       DATE(LEAST(t.todate, s.todate)) 
     - DATE(GREATEST(t.fromdate, s.fromdate)) countdays
  FROM table1 t CROSS JOIN
(
  SELECT '2013-12-14 00:00:00' fromdate,
         '2013-12-29 00:00:00' todate
) s
 WHERE s.fromdate BETWEEN t.fromdate AND t.todate
    OR s.todate   BETWEEN t.fromdate AND t.todate

这是 SQLFiddle 演示

Mysql如何统计从和之间的日子？

2 个答案: