Question

The website I am working on provides a service, where only members can get full access to the content. I am trying to create a ‘sample’ on the homepage that fetches NEW mysql data (that is normally available for members only) every day and provides ALL users with a ‘free sample’ of what the site has to offer.

The database contains over one thousand entries and I would like to find a way to fetch new mysql data from the db every day.

Assuming my database looks like this:

id    cars
1     honda
2     volvo
3     ford
4     audi

I would like the ‘car of the day’ to be ‘honda’ for 24 hours, then ‘ford’ for 24 hours, then ‘audi’ for 24 hours, etc…

this is what I have so far:

<?php 
    //Create mysql connect variable
    $conn = mysql_connect('server', 'username', 'password');
    //kill connection if error occurs
    if(!$conn){
        die('Error: Unable to connect. <br/>' . mysql_error());
    }
    //connect to mysql database
    mysql_select_db("masdswe9", $conn);

    $results = mysql_query("SELECT * FROM cars");

    $name_array = Array();

    while($row = mysql_fetch_array($results)){
        $name_array[] = $row['name'];
    }
    shuffle($name_array);

   /* I would like for this to fetch NEW SQL data every 24 hours, 
   since I am shuffling names above, slot 0 will be different once I 
   come up with a way to fetch new mysql data every 24 hours */
    echo $name_array[0];
?>

Answer 1

I would create a DB table called CarOfTheDay that you can select from (it will just have the ID of the car in the Cars table). Either that or you can have a column carOfTheDay, or change the order of the cars, but I think those are a bit more intrusive.

Create a cron that runs once a day ans writes a random car to CarOfTheDay. Then, you can do what you are doing above, but you don’t have to worry about timing and you will only select one car:

SELECT
   cars
FROM
   CarOfTheDay
   JOIN Cars USING (id)
LIMIT 1

The LIMIT should not be necessary if you stick to one CarOfTheDay.

By the way, use PDO or mysqli rather than mysql_*. Only select columns you need (don’t use SELECT * in production code) .. and only select rows you need (you can randomize in the query).