mysqli_fetch_array没有结果

Question

This is a part of my header file:

    $username = $_COOKIE["empirebattles"];
    $userdata_query = mysqli_query($con,"SELECT * FROM users WHERE username = '$username'");
    $userdata = mysqli_fetch_array($userdata_query, MYSQLI_ASSOC);

I got the value of the cookie, ran a query with it and then fetched the array, why does it not seem to print the correct value when I write:

echo $userdata["username"];

It's probably a small error, but all help is appreciated.

Answer 1

Try this:

   $username = isset($_COOKIE["empirebattles"]) ? $_COOKIE["empirebattles"] : false ;
    if($username){
        $userdata_query = mysqli_query($con,"SELECT * FROM users WHERE username = '$username'");
        $userdata = mysqli_fetch_array($userdata_query, MYSQLI_ASSOC);
        echo $userdata["username"];
    }
    else{

     echo "no username selected!";
    }

Answer 2

this may sound stupid, but have you included your connetion to the database, without a DB connection then you wont get a return. before the query, make sure you have the following

<?php include('Connection_To_Database.php') ?>

you maye have overlooked this