如何分割datetime列到日期和時間，單獨比較

Question

我有一個訪問表

與

  member_id 
      visit_id 
      visit_logout_datetime(values like this... ' 

現在我需要的visit_logout_datetime今天的日期時間屬性比較列...

這裏是兩個條件

1）我需要compare the today date with date從這一領域未來visit_logout_datetime

//這裏我想要做的事....

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

我想單獨比較..

我怎麼能做到這一點..

將在此任何一個請幫助....

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) 

Answer 2

使用MySQL的函數DATE提取日期部分，同樣TIME獲取該部分。