关于日期相减

Question

2个DateTime的日期 相减 我想算出相差不多少天该怎么写？

Answer 1

mysql:
select datediff(d1,d2) from tt

Answer 2

DATEDIFF(expr,expr2) 
DATEDIFF() 返回起始时间 expr和结束时间expr2之间的天数。Expr和expr2 为日期或 date-and-time 表达式。计算中只用到这些值的日期部分。 mysql> SELECT DATEDIFF('1997-12-31 23:59:59','1997-12-30');        -> 1mysql> SELECT DATEDIFF('1997-11-30 23:59:59','1997-12-31');        -> -31

Answer 3

mssql 里面也是用datediff函数
oracle 里面直接减就可以了

Answer 4

MySQL 中用datediff 就行了。http://dev.mysql.com/doc/refman/5.1/zh/functions.html#date-and-time-functions
12.5. 日期和时间函数

Answer 5

mysql> select datediff(curdate(),"2008/01/02");
+----------------------------------+
| datediff(curdate(),"2008/01/02") |
+----------------------------------+
|                              609 |
+----------------------------------+
1 row in set (0.16 sec)

Answer 6

mysql> select date_add(curdate(),interval 23 day);
+-------------------------------------+
| date_add(curdate(),interval 23 day) |
+-------------------------------------+
| 2009-09-25                          |
+-------------------------------------+
1 row in set (0.09 sec)
赠送个函数