Hi All,

I'm fairly new to PHP and really do than you in advance for any hints as to come up with a solution to these problems.

Using PHP and a MySql database.

Problem 1:

I need to come up with a way of counting back 365 number days and during that period count the number of times a specific product was purchased.

Problem 2:

Product expiry. I need to calculate the first day of the fourteenth whole month after a product was purchased..... real head scratcher.



Thanks a ton in advance.

Do you need to solve this in the db, or in php?

1)
in php: mktime() allows you to do time addition/substractions. You can specify negative value, like

PHP Code:

mktime  (date("H"), date("i"), date("s"), date("n"), date("j"), date("Y")-1) 


But I recommand you to do this in the db directly...

in db: Well, for that, it depends your db schema.
If you have 1 table with the articles and 1 with the sales, joined on articles.artId=sales.artFk:

select a.artId as articleId, count(a.artId) as nbrSales
from articles a
  inner join sales s
    on s.artFk=a.artId
where s.dtmSold between now()-interval 1 year and now()
group by a.artId

2)
in php: well, it's much more complicated, and I recommand you the db solution... Again... (Hey, I'm a db guy by trade!)
in db: Using last query as reference it would be

select last_day(s.dtmSold)+interval 1 day+interval 14 month as dtmExpiry
from sales s

Thanks for that, I'll let you know how it turns out when I get back to that section, I put it onto the back burner when I got stumped so I'll let you know in a few days.

Thanks again