计算时间戳小于 24 小时的行数

For the query below, how could I count the number of rows where datesent is less than 24 hours old? (The field datesent is a timestamp).

提前致谢，

约翰

  $message = "SELECT datesent, recipient
               FROM privatemessage 
              WHERE recipient = '$u'";


  $messager = mysql_query($message);

$messagearray = array(); 

推荐答案

使用:

SELECT COUNT(*) AS cnt
  FROM PRIVATEMESSAGE pm
 WHERE pm.datesent >= DATE_SUB(NOW(), INTERVAL 1 DAY)