PDO database query array error

gecekule

Hello
PDO database query array error
PHP Warning: count(): Parameter must be an array or an object that implements Countable in
PHP Warning: str_repeat(): Second argument has to be greater than or equal to 0 in
PHP Warning: array_merge(): Argument #2 is not an array in
PHP Fatal error: Uncaught PDOException: SQLSTATE[HY093]: Invalid parameter number: no parameters were bound in
PDOStatement->execute(NULL)

$_SESSION['satellite_ids_json'] = ["1","2","3","4"]

        $arr = json_decode($_SESSION['satellite_ids_json']);
        $in  = str_repeat('?,', count($arr) - 1) . '?';
        $sql = "SELECT * FROM satellite WHERE satellite_lnb_type=? AND id IN ($in)";
        $stm = $PDOdatabase->prepare($sql);
        $params = array_merge(['MDULNB'], $arr);
        $stm->execute($params);

NogDog

gecekule PHP Warning: count(): Parameter must be an array or an object that implements Countable in

Start by figuring out why $arr is not an array or iterable object at that point. Maybe do a var_dump() of it after the json_decode() to see what you actually have?

gecekule

var_dump($arr);

array (size=4)
0 => string '1' (length=1)
1 => string '2' (length=1)
2 => string '3' (length=1)
3 => string '4' (length=1)
It always gave an error yesterday, today it didn't fail I couldn't understand the problem
Thank you

gecekule

I solved the problem,
I added this to the include file, the problem is fixed.

if(!isset($_SESSION)){
  session_start();
}

NogDog

Glad you figured it out. While that session check is probably fine, you might want to consider this as being a bit more robust (and maybe a bit more explicit?):

if(session_status() == PHP_SESSION_NONE) {
  session_start();
}

gecekule

Once the problem was fixed, then the problem happened again I couldn't understand
So, while there is data in the session, it acts as if it doesn't exist.
So I looked for different ways
Satellite ids come as arrays on another page and creating json on the same page
I'm using the above code on another page
There is "$ _SESSION ['satellite_ids_json']" data here but I don't understand it gives an error
I used it in the above code by taking it into the session as an array on the satellite page.
I'll try with this check

NogDog

Just because this came up recently elsewhere, be careful with use of sub-domains (include www.), as that can impact whether or not the client sends the session cookie to a given page. It might explain why it would work in some situation and not in others, as if some links just specify "yourdomain.com' but others hit 'www.yourdomain.com', you may not receive the session cookie back from the browser. You can help prevent any such problem with:

<?php
session_set_cookie_params(60 * 60 * 24, '/', '.yourdomain.com'); // note leading dot for domain
session_start();

This is a useful thing to stick into any start-up script you require on each page, as the cookie will then be exchanged regardless of whether any sub-domain is specified or not.