PHP设置进程的间隔

Question

I have an API fetcher script that reads values from XML files and updates data to mysql. It updates the database everytime it's called via ajax.

Now I want to set an interval for about a day before the query gets updated. Which php function or method should I use?

I think I should make myself a little more clear, these are the steps:

1. xml file read with php

2. Echo the results.

3. --->If (mysql updated time > 24*60*60 seconds) update the db

   --->if not, do nothing.

I can't figure out how should I process the step (3)

Answer 1

Well! as far as i understood your question. I think you should do with SQL not with PHP.

Save update time in db with query of Insert. And call a stored procedure every time you update. like in MySQL:

Begin
    //Adding updtime column value into a Variable called @a
    select @a:=updtime from abc order by id desc limit 1;

    //DATE_ADD() is a function of MySQL to get Time after adding Hours or Minutes etc. More can be found in MySQL Manual online
    if DATE_ADD(@a, INTERVAL 24 HOUR) > now()
    then insert into abc values ('XML',now());
    end if;
End

You can also do it without a variable and that would be much better as

    if DATE_ADD((select updtime from abc order by id desc limit 1), INTERVAL 24 HOUR) > now()