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Table of Contents
The Quiz App Version 2
At this point, you should have a basic, working quiz that is pulling questions from a database. If not, take a look at The Quiz App to get started.
This is what your code should look like before we get started, make sure you understand each line (and that it works). Look at the Troubleshooting section below if you run into problems.
Sessions
You can store information in a session, which can be accessed on each page load. We'll use a session now to track which questions have already been answered, and we can record the name of person taking the quiz for a future high score table.
You can access what is in a session array in the same way you can see what is in a request array:
print_r($_SESSION);
Let's understand sessions first, separate from the quiz code. Create a new test page and call it testsession.php:
<?php session_start(); ?> <html> <body> <?php if(!empty($_REQUEST)) { print_r($_REQUEST); } if(!empty($_REQUEST['visitor_name'])) { $_SESSION['visitor_name'] = $_REQUEST['visitor_name']; } if(!empty($_SESSION['visitor_name'])) { echo "<p>Welcome ".htmlentities($_SESSION['visitor_name'])."</p>"; } ?> <form method='post' action=''> <input type='text' name='visitor_fullname' /> <input type='submit' name='username_button' value='Login' /> </form> <?php ?>
The above code has an error in it. See if you can spot where. I'll talk people through it.
I'll add to this page as we go through on the night.
Some functions we'll need:
phpinfo();
Troubleshooting
I just get a blank white screen or HTTP ERROR 500
Add some error reporting to the very top of your code:
quiz.old.php:error_reporting(E_ALL);
ini_set("display_errors", 1);
Remember to also add to any other files you might be including [or require()'ing]
I'm getting an ''Uncaught PDOException: SQLSTATE[HY000] [1045] Access denied'' error
Make sure you are using the correct credentials in questions_from_db.php. If you are unsure, you can set them again by connecting to your mysql server on the terminal:
sudo mysql -u root
Then, inside the mysql client, create a user called ‘coding_username’, with the password ‘cheese’ and give it access to the newly created ‘coding’ database:
grant all on coding.* to coding_username@localhost identified by 'cheese'; quit
Notice we use 'coding_username' - make sure that is what is in your questions_from_db.php file.
