MySQL：选择日期加上6个月（如果少于now（）则加上1个月）

Question

I have a given date:

2013-12-20

This is an issue date of a product where the product expiries in 6 months from the date of issue. The expiration date it is not stored so I want to check from the given issue date if it is expiring in the next month of now().

So my guess would be to add 6 months to the issue date and check now + interval of 1 month if it is expiring?

Here is what I tried:

SELECT * FROM `products` WHERE DATE_ADD(`issue_date`,INTERVAL 6 MONTH) 
< DATE(NOW() + INTERVAL 1 MONTH) ORDER BY `issue_date` ASC

What I'm I doing wrong?

Answer 1

SELECT * FROM products WHERE Now() <= DATE_ADD(issue_date, INTERVAL 7 MONTH) && Now() >= DATE_ADD(issue_date, INTERVAL 6 MONTH) ORDER BY issue_date ASC;

• The first item that has to be returned has due date today (so issue date + 6 months = today);
• than due date tomorrow (so issue date + 6 months + 1 day = today);
• ...
• than due date one month from today(so issue date + 6 months + 1 month = issue date + 7 months = today)

Answer 2

here's a suggestions which might help
$date = date("ymd", strtotime(" +6 months"));
this will result in date 6 months later from current date:
similarly,
for one month from current date
$date = date("ymd", strtotime(" +1 months"));

Answer 3

SELECT * FROM `products` 
WHERE NOW() >= DATE_ADD(`issue_date`,INTERVAL 5 MONTH) 
  AND NOW() <= DATE_ADD(`issue_date`,INTERVAL 6 MONTH) 
ORDER BY `issue_date` ASC

Answer 4

Your query says to select all the products that will expire within a month or had already expired. You could use between clause

SELECT * FROM `products` WHERE DATE_ADD(`issue_date`,INTERVAL 6 MONTH) between NOW() and  DATE(NOW() + INTERVAL 1 MONTH) ORDER BY `issue_date` ASC

Between clause in Mysql

Answer 5

If you want to check if the product expiries in 6 months from the date of issue and if it is expiring in the next month, the it is better to add this 1 month to the 6th in the query:

SELECT * FROM products WHERE issue_date <= DATE_ADD(issue_date,INTERVAL 7 MONTH)
ORDER BY issue_date ASC;

Answer 6

尝试这个

SELECT * FROM `products` where DATE_ADD(`issue_date`,INTERVAL 6 MONTH) < CURDATE()

Answer 7

After a few of these answers I ended up working it out with this:

SELECT * FROM  `products` 
WHERE DATE_ADD(  `issue_date` , INTERVAL 6 MONTH ) 
< DATE(NOW() + INTERVAL 1 MONTH)