PHP MySQL dont get last selected - php

Question

i have a mysql Table with some rows.
The Select gets one (LIMIT 1) row. After a counter it reloads and get random another row. But sometimes he get the same (cause random).
How can i setup that he dont get the last row?
The problem is, i cannot do that in mysql. I must do that in the SESSION or only on that site.
I tried that:
$_SESSION['ads'] .= ','.$adid;
put that adid in "ads" SESSION and read it before SELECT here
session_start();
$ads = substr($_SESSION['ads'], 1);
$ads = str_replace(",", "','", $_SESSION['ads']);
In the SELECT is that
AND id NOT IN ('".$ads."')
But sometimes, i dont know why, he save two items or something... i dont find out why, cause the SELECT is LIMIT 1
Any ideas how to do that or is there a mysql function?
For any reason, the script is load two times the SELECT or something
This is the code:
$query = "SELECT * FROM ads ORDER BY RAND() LIMIT 1;";
while($row = $result->fetch_assoc()) {
$adid = $row["id"];
$_SESSION['ads'][] = $adid;
}
echo 'adid: '. $adid;
print_r($_SESSION['ads']);
There he print like that:
Array
(
[0] => 6
[1] => 3
)
I dont know, why he puts 2 in there. Cause the echo of the $adid shows only one!

Answer 1

Try something like this maybe :
1/ Create a new session and create an empty array :
session_start();
if (empty($_SESSION['ads']))
$_SESSION['ads'] = array();
2/ Do you select and add the id in this array :
if (empty($_SESSION['ads']) {
// 1. Do your select with no where condition
// 2. Fetch the result
$data = /* result of the select */;
// 3. Add the selected id in your session array
$_SESSION['ads'][] = $data['id'];
} else {
// 1. Do your select but with a WHERE condition
$query = "SELECT...
WHERE id NOT IN ( " . implode( "', '" , $_SESSION['ads'] ) . " )";
// 2. Fetch the result
$data = /* result of the select */;
// 3. Add the selected id in your session array
$_SESSION['ads'][] = $data['id'];
}
Is it what you are looking for?