SQL How to make a select query with a var php condition - php

Question

hello I want to be able to display only the data from my database where the cookie id is equal to that of the database
For now it does not work, the cookie is well stored because I can display it is the sql part which does not work, I have no error code in the console
I tried a first code which did not work then I went on google to seek examples of codes which would have similarities to mine, I did not find anything convincing, I searched on stack over flow I found a topic that partially referred to it, so I applied the code but it didn't work.
here is the site where it is hosted : comparateur.innovations-Ux.com/compare.php
here is my code :
echo $_COOKIE["user_id"];
$user = "innovatiesvictor";
$pass = ".................";
try {
$dbh = new PDO('mysql:host=.............;dbname=innovatiesvictor', $user, $pass);
foreach($dbh->query("SELECT * from QUESTIONNAIRE WHERE SID = '{$_COOKIE["user_id"]}' ") as $row)
{
echo 'hello world';
}
$dbh = null;
} catch (PDOException $e) {
print "Erreur !: " . $e->getMessage() . "<br/>";
die();
}
?>

Answer 1

try to add a variable instead:
$cookie = $_COOKIE["user_id"];
and then turn this:
foreach($dbh->query("SELECT * from QUESTIONNAIRE WHERE SID = '{$_COOKIE["user_id"]}' ") as $row)
into this:
foreach($dbh->query("SELECT * from QUESTIONNAIRE WHERE SID = '$cookie'") as $row)
Hope it helps you.

Answer 2

If I am correct you are trying to foreach wrong object.
After you query you set fetch mode, for ex.:
$q->setFetchMode(PDO::FETCH_ASSOC);
Then you loop over rows with
<?php while ($row = $q->fetch()): ?>
That is first example I find.
https://www.mysqltutorial.org/php-querying-data-from-mysql-table/
Hope it helps.