C.6 Chapter 7
C.6.1 Exercise 1:
<?php
require 'DB.php';
$db = DB::connect('mysql://hunter:w)mp3s@db.example.com/restaurant');
if (DB::isError($db)) { die("Can't connect: " . $db->getMessage( )); }
$db->setErrorHandling(PEAR_ERROR_DIE);
$db->setFetchMode(DB_FETCHMODE_ASSOC);
$dishes = $db->getAll('SELECT dish_name,price FROM dishes ORDER BY price');
if (count($dishes) > 0) {
print '<ul>';
foreach ($dishes as $dish) {
print "<li> $dish[dish_name] ($dish[price])</li>";
}
print '</ul>';
} else {
print 'No dishes available.';
}
?>
C.6.2 Exercise 2:
<?php
require 'DB.php';
require 'formhelpers.php'; // load the form element printing functions
$db = DB::connect('mysql://hunter:w)mp3s@db.example.com/restaurant');
if (DB::isError($db)) { die("Can't connect: " . $db->getMessage( )); }
$db->setErrorHandling(PEAR_ERROR_DIE);
$db->setFetchMode(DB_FETCHMODE_ASSOC);
if ($_POST['_submit_check']) {
if ($form_errors = validate_form( )) {
show_form($form_errors);
} else {
process_form( );
}
} else {
show_form( );
}
function show_form($errors = '') {
if ($errors) {
print 'You need to correct the following errors: <ul><li>';
print implode('</li><li>',$errors);
print '</li></ul>';
}
// the beginning of the form
print '<form method="POST" action="'.$_SERVER['PHP_SELF'].'">';
print '<table>';
// the price
print '<tr><td>Price:</td><td>';
input_text('price', $_POST);
print '</td></tr>';
// form end
print '<tr><td colspan="2"><input type="submit" value="Search Dishes">";
print '</td></tr>';
print '</table>';
print '<input type="hidden" name="_submit_check" value="1"/>';
print '</form>';
}
function validate_form( ) {
$errors = array( );
if (! strval(floatval($_POST['price'])) == $_POST['price']) {
$errors[ ] = 'Please enter a valid price.';
} elseif ($_POST['price'] <= 0) {
$errors[ ] = 'Please enter a price greater than 0.';
}
return $errors;
}
function process_form( ) {
global $db;
$dishes = $db->getAll('SELECT dish_name, price FROM dishes WHERE price >= ?',
array($_POST['price']));
if (count($dishes) > 0) {
print '<ul>';
foreach ($dishes as $dish) {
print "<li> $dish[dish_name] ($dish[price])</li>";
}
print '</ul>';
} else {
print 'No dishes match.';
}
}
?>
C.6.3 Exercise 3:
<?php
require 'DB.php';
require 'formhelpers.php'; // load the form element printing functions
$db = DB::connect('mysql://hunter:w)mp3s@db.example.com/restaurant');
if (DB::isError($db)) { die("Can't connect: " . $db->getMessage( )); }
$db->setErrorHandling(PEAR_ERROR_DIE);
$db->setFetchMode(DB_FETCHMODE_ASSOC);
// get the array of dish names from the database
$dish_names = array( );
$res = $db->query('SELECT dish_name FROM dishes');
while ($row = $res->fetchRow( )) {
$dish_names[ ] = $row['dish_name'];
}
if ($_POST['_submit_check']) {
if ($form_errors = validate_form( )) {
show_form($form_errors);
} else {
process_form( );
}
} else {
show_form( );
}
function show_form($errors = '') {
global $db;
if ($errors) {
print 'You need to correct the following errors: <ul><li>';
print implode('</li><li>',$errors);
print '</li></ul>';
}
// the beginning of the form
print '<form method="POST" action="'.$_SERVER['PHP_SELF'].'">';
print '<table>';
// dish select menu
print '<tr><td>Dish:</td><td>';
input_select('dish_name', $_POST, $GLOBALS['dish_names']);
print '</td></tr>';
// form end
print '<tr><td colspan="2"><input type="submit" value="Search Dishes">';
print '</td></tr>';
print '</table>';
print '<input type="hidden" name="_submit_check" value="1"/>';
print '</form>';
}
function validate_form( ) {
$errors = array( );
if (! array_key_exists($_POST['dish_name'], $GLOBALS['dish_names'])) {
$errors[ ] = 'Please select a valid dish.';
}
return $errors;
}
function process_form( ) {
global $db;
// Translate $_POST['dish_name'] (which is a number) into a
// name like "Walnut Bun"
$dish_name = $GLOBALS['dish_names'][ $_POST['dish_name'] ];
$dish_info = $db->getRow('SELECT dish_id, dish_name, price, is_spicy
FROM dishes WHERE dish_name = ?',
array($dish_name));
if (count($dish_info) > 0) {
print '<ul>';
print "<li> ID: $dish_info[dish_id]</li>";
print "<li> Name: $dish_info[dish_name]</li>";
print "<li> Price: $dish_info[price]</li>";
print "<li> Is Spicy: $dish_info[is_spicy]</li>";
print '</ul>';
} else {
print 'No dish matches.';
}
}
?>
C.6.4 Exercise 4:
The structure of the customers table:
CREATE TABLE customers (
customer_id INT UNSIGNED
customer_name VARCHAR(255),
phone VARCHAR(15),
favorite_dish_id INT
)
The form that inserts a new customer:
<?php
require 'DB.php';
require 'formhelpers.php';
// Connect to the database
$db = DB::connect('mysql://hunter:w)mp3s@db.example.com/restaurant');
if (DB::isError($db)) { die ("Can't connect: " . $db->getMessage( )); }
// Set up automatic error handling
$db->setErrorHandling(PEAR_ERROR_DIE);
// Set up fetch mode: rows as associative arrays
$db->setFetchMode(DB_FETCHMODE_ASSOC);
// get the array of dish names from the database
$dish_names = array( );
$res = $db->query('SELECT dish_id,dish_name FROM dishes');
while ($row = $res->fetchRow( )) {
$dish_names[ $row['dish_id'] ] = $row['dish_name'];
}
// The main page logic:
// - If the form is submitted, validate and then process or redisplay
// - If it's not submitted, display
if ($_POST['_submit_check']) {
// If validate_form( ) returns errors, pass them to show_form( )
if ($form_errors = validate_form( )) {
show_form($form_errors);
} else {
// The submitted data is valid, so process it
process_form( );
}
} else {
// The form wasn't submitted, so display
show_form( );
}
function show_form($errors = '') {
global $dish_names;
// If the form is submitted, get defaults from submitted variables
if ($_POST['_submit_check']) {
$defaults = $_POST;
} else {
// Otherwise, no defaults
$defaults = array( );
}
// If errors were passed in, put them in $error_text (with HTML markup)
if ($errors) {
$error_text = '<tr><td>You need to correct the following errors:';
$error_text .= '</td><td><ul><li>';
$error_text .= implode('</li><li>',$errors);
$error_text .= '</li></ul></td></tr>';
} else {
// No errors? Then $error_text is blank
$error_text = '';
}
// Jump out of PHP mode to make displaying all the HTML tags easier
?>
<form method="POST" action="<?php print $_SERVER['PHP_SELF']; ?>">
<table>
<?php print $error_text ?>
<tr><td>Customer Name:</td>
<td><?php input_text('customer_name', $defaults) ?></td></tr>
<tr><td>Phone Number:</td>
<td><?php input_text('phone', $defaults) ?></td></tr>
<tr><td>Favorite Dish:</td>
<td><?php input_select('favorite_dish_id', $defaults, $dish_names); ?></td></tr>
<tr><td colspan="2" align="center"><?php input_submit('save','Add Customer'); ?>
</td></tr>
</table>
<input type="hidden" name="_submit_check" value="1"/>
</form>
<?php
} // The end of process_form( )
function validate_form( ) {
global $dish_names;
$errors = array( );
// customer_name is required
if (! strlen(trim($_POST['customer_name']))) {
$errors[ ] = 'Please enter the customer name.';
}
// phone number is required and must look right
if (! strlen(trim($_POST['phone']))) {
$errors[ ] = 'Please enter a phone number';
} elseif (! preg_match('/^\(\d{3}\) ?\d{3}-\d{4}$/', $_POST['phone'])) {
$errors[ ] = 'Please enter a phone number in the format (XXX) XXX-XXXX.';
}
// favorite dish is required
if (! array_key_exists($_POST['favorite_dish_id'], $dish_names)) {
$errors[ ] = 'Please select a favorite dish.';
}
return $errors;
}
function process_form( ) {
// Access the global variable $db inside this function
global $db;
// Get a unique ID for this customer
$customer_id = $db->nextID('customers');
// Insert the new customer into the table
$db->query('INSERT INTO customers (customer_id, customer_name, phone, favorite_
dish_id) VALUES (?,?,?,?)',
array($customer_id, $_POST['customer_name'], $_POST['phone'],
$_POST['favorite_dish_id']));
// Tell the user that we added a customer.
print 'Added ' . htmlentities($_POST['customer_name']) . ' to the database.';
}
?>
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