嵌套函数;今天(datediff (student_info & # 39; 1999 - 8 - 31日& # 39;

Nested functions;.todays(datediff(student_info,'1999-8-31'))

我是SQL和php的新手。我想通过dob(表字段)和固定日期(;)的差异计算学生的年龄(以月为单位)。31-8-2016)。还要将值存储在名为age的字段中

使用MYSQL

SELECT 12 * (YEAR(DateOfService) 
              - YEAR(BirthDate)) 
       + (MONTH(DateOfService) 
           - MONTH(BirthDate)) AS months 
FROM table

使用PHP

$date1 = '2000-01-25';
$date2 = '2010-02-20';
$ts1 = strtotime($date1);
$ts2 = strtotime($date2);
$year1 = date('Y', $ts1);
$year2 = date('Y', $ts2);
$month1 = date('m', $ts1);
$month2 = date('m', $ts2);
$diff = (($year2 - $year1) * 12) + ($month2 - $month1);