Using Sessions In Php Mysql Multi-Page Website.

[wesmith4]

I am new at using PHP and MySQL.

I am using a login.php script from Larry's book, and a similiar script I call view_coursegrades.php.

I want to be able to identify a teacher who logs into my site, and then use a query based on that identification to allow them to edit and view grades in only the courses where they are the teacher.

The following is some of the script:

 

<?php # Script 12.12 - login.php #4

// This page processes the login form submission.

// The script now stores HTTP_USER_AGENT value for added security.

 

// Check if the form has been submitted:

if ($_SERVER['REQUEST_METHOD'] == 'POST') {

 

    // Need two helper files:

    require ('includes/login_functions.inc.php');

    require ('./mysqli_connect.php');

 

    // Check the login:

    list ($check, $data) = check_login($dbc,$_POST['email'], $_POST['pass']);

    

    if ($check) { // OK!

 

        // Set the session data:

        session_start();

        $_SESSION['user_id'] = $data['user_id'];

        $_SESSION['first_name'] = $data['first_name'];

 

        // Store the HTTP_USER_AGENT:

        $_SESSION['agent'] = md5($_SERVER['HTTP_USER_AGENT']);

 

        // Redirect:

        redirect_user('loggedin.php');

 

     } else { // Unsuccessful!

 

        // Assign $data to $errors for login_page.inc.php:

        $errors = $data;

 

     }

 

     mysqli_close($dbc); // Close the database connection.

     

} // End of the main submit conditional.

 

// Create the page:

include ('includes/login_page.inc.php');

?>

======================================

 

<?php # Script 10.1 - view_coursegrades.php #3

// This script retrieves the grades for courses.

// This version links to edit and delete pages.

session_start(); //Access the existing session.

echo '<h2>The number below is for teacher ID.</h2>';

echo '<h2>{$_SESSION['user_id']}</h2>';

 

$page_title = 'View Course Grades.';

include ('includes/header.html');

echo '<h1>Course Grades at ASMWA</h1>';

 

require ('./mysqli_connect.php');

 

// Define the query:

$q = "SELECT COSID,LastName,FirstName,CourseTitle,TeaLastName, TeacherID, GradeEarned FROM TranscriptView";

$r = @mysqli_query ($dbc, $q);

 

// Count the number of returned rows:

$num = mysqli_num_rows($r);

===================================

 

I have been unable to filter the query to select only records from the database where the TeacherID is for the teacher who logged in.

 

Can anyone help me?

 

Wes Smith

 

[margaux]

What about

$q = "SELECT COSID,LastName,FirstName,CourseTitle,TeaLastName, TeacherID, GradeEarned FROM TranscriptView WHERE TeacherID = $_SESSION['user_id']";