返回mysql结果并在另一个函数中使用

Question

I have a php function that gets a users ID based on their studentid.

function getID() {
    require "connect.php";

    $id = mysqli_query($connection, "SELECT id, studentid FROM users
WHERE studentid = '".$_SESSION["studentid"]."'")  or die(mysqli_error($connection));


$userID = mysqli_fetch_assoc($id);
echo $userID['id']; // Just to make sure it works

}

I would like to use the result of this function in another function but dont know how.

I would specifically like to use it in a where clause , e.g:

WHERE id = getID());

Answer 1

Return $userID in you getId() function, and call the function when you build the query :

mysqli_query($connection, "SELECT id FROM table
WHERE id = '".getId()."'");