MySQL PHP按随机顺序一段时间？

Question

For example, say if you wanted a random result every 10 minutes. Is there a way to achieve this with ORDER BY RAND()?

$fetch = mysqli_query($conn, "
  SELECT * 
    FROM food 
    JOIN food_images ON food.size = food_images.size 
    ORDER BY RAND()
"); 

I also am using a JOIN and worried if this might affect the answers. Thank you!

Answer 1

I don't have a MySQL server in front of me so most of this is a guess, but you might try as follows:

You can generate a number that changes only once every ten minutes by taking the system time in seconds, dividing by the number of seconds in ten minutes, and then casting to an integer:

$seed = (int) (time() / 600);

Then pass this value to MySQL's RAND() function as a parameter to seed the RNG, and you should get a repeatable sequence that changes every ten minutes:

$stmt = mysqli_prepare($conn, 'SELECT ... ORDER BY RAND(?)');
mysqli_stmt_bind_param($stmt, 'i', $seed);