how can I use $conn within a function in another php file

Question

I defined $conn in a file and now I am trying to use it within a function in another file. I used the 'global' keyword but it still gives me errors. This is the code

<?php
function redirect_to($new_location){
    header("Location: " . $new_location);
    exit;
}
function query($query){
    global $conn;
    return mysqli_query($conn,$query);
}

function confirm($result){
    global $conn;
    if(!$result){
        die("Query Failed ". mysqli_error($conn));
    }
}

function fetch_array($result){
    return mysqli_fetch_array($result);
}

function getbooks(){
    $sql = query("SELECT * FROM books ORDER BY Id DESC");
    confirm($sql);

    while($row = fetch_array($sql)){
        echo $row['Author'];    
    }


}
?>

this is the file where I defined conn

<?php
    $conn = mysqli_connect("localhost", "root", "azonto47","Libraria");

    if (!$conn){
        die("Connection failed: ".mysqli_connect_error());
    }
?>

Answer 1

您必须包含定义$conn的文件。