php - 如何在PHP中计算多个到期日期

如果我想在PHP中生成多个到期日期，请问能给我推荐最好的解决方案吗？
我有这样的事情：

Name   |  activation_date  |  months
--------------------------------------
Record1    04/05/2016           3
Record2    01/01/2016           6
Record3    12/12/2015           12

对于record1，我使用以下function，

$expriration_date = date('Y-m-d', strtotime("+{$row['months']} months", strtotime($expriration_date)));

要从expiration date开始生成"activation_date"，然后将其保存到我的SQL Database中。

问题是我想生成多个周期性的expiration dates。

例如，对于record1，到期日期应为：04/08/2016，04/11/2016，04/02/2016，等等，为5年，我希望对所有记录都这样做。
在五年内，Record1应该具有20个到期日期，Record2应该具有10个到期日期，依此类推。

编辑

间隔时间可以是3、6、12、24、36、48和50个月，我想生成5年的定期到期日期。

如何在PHP中做到这一点？
而且，有没有办法通知用户最近的到期日期呢？
我读过有关cron-job的文章：这是唯一的解决方案？

感谢你的支持。

最佳答案

您可以使用简单的for loop

 for ($m = $months; $m <=60 ; $m += $months){
   //add $m to activation_date
   $expriration_date = DateTime::createFromFormat('Y-m-d', $activation_date);
   $expriration_date->add(new DateInterval('P'.$m.'M'));
   //do something with $expriration_date
 }

您可以通过查询来做到这一点（但不要发布使用的数据库引擎）。
该查询适用于大多数流行的数据库引擎：

WITH
  intervals AS
   ( SELECT 1 AS n, 3 AS m
     UNION ALL SELECT 2 AS n, 3 AS m
     UNION ALL SELECT 3 AS n, 3 AS m
     UNION ALL SELECT 4 AS n, 3 AS m
     UNION ALL SELECT 5 AS n, 3 AS m
     UNION ALL SELECT 6 AS n, 3 AS m
     UNION ALL SELECT 7 AS n, 3 AS m
     UNION ALL SELECT 8 AS n, 3 AS m
     UNION ALL SELECT 9 AS n, 3 AS m
     UNION ALL SELECT 10 AS n, 3 AS m
     UNION ALL SELECT 11 AS n, 3 AS m
     UNION ALL SELECT 12 AS n, 3 AS m
     UNION ALL SELECT 13 AS n, 3 AS m
     UNION ALL SELECT 14 AS n, 3 AS m
     UNION ALL SELECT 15 AS n, 3 AS m
     UNION ALL SELECT 16 AS n, 3 AS m
     UNION ALL SELECT 17 AS n, 3 AS m
     UNION ALL SELECT 18 AS n, 3 AS m
     UNION ALL SELECT 19 AS n, 3 AS m
     UNION ALL SELECT 20 AS n, 3 AS m
     UNION ALL SELECT 1 AS n, 6 AS m
     UNION ALL SELECT 2 AS n, 6 AS m
     UNION ALL SELECT 3 AS n, 6 AS m
     UNION ALL SELECT 4 AS n, 6 AS m
     UNION ALL SELECT 5 AS n, 6 AS m
     UNION ALL SELECT 6 AS n, 6 AS m
     UNION ALL SELECT 7 AS n, 6 AS m
     UNION ALL SELECT 8 AS n, 6 AS m
     UNION ALL SELECT 9 AS n, 6 AS m
     UNION ALL SELECT 10 AS n, 6 AS m
     UNION ALL SELECT 1 AS n, 12 AS m
     UNION ALL SELECT 2 AS n, 12 AS m
     UNION ALL SELECT 3 AS n, 12 AS m
     UNION ALL SELECT 4 AS n, 12 AS m
     UNION ALL SELECT 5 AS n, 12 AS m)
SELECT name, your_db_func_to_add_month(activation_date, n * m) AS expiration_dates
FROM something
INNER JOIN intervals ON months = m
WHERE activation_date BETWEEN your_db_func_to_add_month(:testdate, -60) AND :testdate

：testdate是绑定到查询的参数，
your_db_func_to_add_month例如在mysql中：

DATE_ADD(:testdate, INTERVAL 60 MONTH)

编辑：
如果使用以上数据定义表间隔，则只需选择。对于MySQL，此查询如下所示：

SELECT name, DATE_ADD(activation_date, INTERVAL n * m MONTH) (activation_date, n * m) AS expiration_dates
FROM something
INNER JOIN intervals ON months = m
WHERE activation_date BETWEEN DATE_ADD(:testdate, - INTERVAL 60 MONTH) AND :testdate

关于php - 如何在PHP中计算多个到期日期，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/36446325/