如何将datetime列拆分为日期和时间并单独进行比较

Question

我有一张访问桌

与列

            member_id
           visit_id
           visit_logout_datetime(values like this... '

现在我需要将visit_logout_datetime与今天的日期时间属性进行比较...

这是两个条件

1)我需要compare the today date with date来自这个字段visit_logout_datetime

//这里我想做点什么......

2)我需要比较 present time with the time in this field visit_logout_datetime

我想个别比较..

我怎样才能做到这一点 ..

任何人都会对此有所帮助....

Answer 1

mysql> select cast('2011-10-24 15:20:10' as date);
+-------------------------------------+
| cast('2011-10-24 15:20:10' as date) |
+-------------------------------------+
| 2011-10-24                          |
+-------------------------------------+
1 row in set (0.00 sec)

mysql> select cast('2011-10-24 15:20:10' as time);
+-------------------------------------+
| cast('2011-10-24 15:20:10' as time) |
+-------------------------------------+
| 15:20:10                            |
+-------------------------------------+
1 row in set (0.00 sec)