php - 如何添加where子句以及如何获取两个日期的月份差异

Question

参数时如何计算列数？

我需要计算所有客户，当您将今天的日期/当前(例如；2013-10-28)减去出生日期列(例如；2001-15-13)时返回“<= 6个月”

我有一个 mysql 查询:

$query = 'SELECT  b.record_number,
CONCAT(b.fname," ",b.lname) AS fullname,
province.area_name AS province,
district.area_name AS district,
llg.area_name AS llg,
office.area_name AS office, 
c.clinic_name,
a.feeding_type, 
COUNT(NOW, b.date_birth), - this is my code
b.date_birth,               
FROM tbl_records AS a
JOIN tbl_client AS b ON a.client_id = b.ID
JOIN tbl_clinic AS c ON a.clinic_id = c.ID
JOIN tbl_area AS llg ON c.llg_id = llg.ID
JOIN tbl_area AS district ON llg.parent_ids = district.ID
JOIN tbl_area AS province ON district.parent_ids = province.ID 
JOIN tbl_area AS office ON office.ID = a.office_id
WHERE a.date >= :start_date AND a.date <= :end_date 
AND a.feeding_type <> "NULL" AND a.office_id = :office_id
GROUP BY a.client_id';

Answer 1

要获取MYSQL中日期之间的差异，可以使用DATEDIFF

http://dev.mysql.com/doc/refman/5.6/en/date-and-time-functions.html#function_datediff

从你的问题来看，我认为你正在尝试返回一些间隔并根据该间隔返回一个字符串。您需要设置一系列 IF 语句。

https://dev.mysql.com/doc/refman/5.0/en/if.html

更新:

您可以使用PERIOD-DIFF获得几个月的差异，但您需要更改日期的格式。您可以使用 GET_FORMAT

执行此操作

http://dev.mysql.com/doc/refman/5.6/en/date-and-time-functions.html#function_get-format

http://dev.mysql.com/doc/refman/5.6/en/date-and-time-functions.html#function_period-diff