Mwamitovi · January 29, 2025 06:20
diff --git a/8_dbs.php b/8_dbs.php
 <?php
 // Chapter-8: Exercises

 // The following exercises use a database table called dishes with the following structure:
 // -- CREATE TABLE dishes (
 // -- dish_id INT,
 // -- dish_name VARCHAR(255),
 // -- price DECIMAL(4,2),
 // -- is_spicy INT
 // -- )
 // Here is some sample data to put into the dishes table:
 // -- INSERT INTO dishes VALUES (1,'Walnut Bun',1.00,0)
 // -- INSERT INTO dishes VALUES (2,'Cashew Nuts and White Mushrooms',4.95,0)
 // -- INSERT INTO dishes VALUES (3,'Dried Mulberries',3.00,0)
 // -- INSERT INTO dishes VALUES (4,'Eggplant with Chili Sauce',6.50,1)
 // -- INSERT INTO dishes VALUES (5,'Red Bean Bun',1.00,0)
 // -- INSERT INTO dishes VALUES (6,'General Tso''s Chicken',5.50,1)

 // Question-1

 // 1. Write a program that lists all of the dishes in the table, sorted by price.

 // Answer-1

 try {
    // Connect
    $db = new PDO('sqlite:/tmp/restaurant.db');
    // Set up exceptions on DB errors
    $db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
    $stmt = $db->query('SELECT * FROM dishes ORDER BY price');
    $dishes = $stmt->fetchAll();
    if (count($dishes) == 0) {
        $html = '<p>No dishes to display</p>';
    } else {
        $html = "<table>\n";
        $html .= "<tr><th>Dish Name</th><th>Price</th><th>Spicy?</th></tr>\n";
        foreach ($dishes as $dish) {
            $html .= '<tr><td>' .
                htmlentities($dish['dish_name']) . '</td><td>$' .
                sprintf('%.02f', $dish['price']) . '</td><td>' .
                ($dish['is_spicy'] ? 'Yes' : 'No') . "</td></tr>\n";
        }
        $html .= "</table>";
    }
 } catch (PDOException $e) {
    $html = "Can't show dishes: " . $e->getMessage();
 }
 print $html;

 // Question-2

 // 2. Write a program that displays a form asking for a price. When the form is submitted, 
 // the program should print out the names and prices of the dishes whose price is at least the submitted price. 
 // Don’t retrieve from the database any rows or columns that aren’t printed in the table.

 // Answer-2

 // Load the form helper class
 require 'FormHelper.php';
 // Connect to the database
 try {
    $db = new PDO('sqlite:/tmp/restaurant.db');
 } catch (PDOException $e) {
    print "Can't connect: " . $e->getMessage();
    exit();
 }
 // Set up exceptions on DB errors
 $db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
 // Set up fetch mode: rows as objects
 $db->setAttribute(PDO::ATTR_DEFAULT_FETCH_MODE, PDO::FETCH_OBJ);
 // The main page logic:
 // - If the form is submitted, validate and then process or redisplay
 // - If it's not submitted, display
 if ($_SERVER['REQUEST_METHOD'] == 'POST') {
    // If validate_form() returns errors, pass them to show_form()
    list($errors, $input) = validate_form();
    if ($errors) {
        show_form($errors);
    } else {
        // The submitted data is valid, so process it
        process_form($input);
    }
 } else {
    // The form wasn't submitted, so display
    show_form();
 }
 function show_form($errors = array())
 {
    // Set up the $form object with proper defaults
    $form = new FormHelper();
    // All the HTML and form display is in a separate file for clarity
    include 'price-form.php';
 }

 function validate_form()
 {
    $input = array();
    $errors = array();
    // Minimum price must be a valid floating-point number
    $input['min_price'] = filter_input(
        INPUT_POST,
        'min_price',
        FILTER_VALIDATE_FLOAT
    );
    if ($input['min_price'] === null || $input['min_price'] === false) {
        $errors[] = 'Please enter a valid minimum price.';
    }
    return array($errors, $input);
 }

 function process_form($input)
 {
    // Access the global variable $db inside this function
    global $db;
    // Build up the query
    $sql = 'SELECT dish_name, price, is_spicy FROM dishes WHERE
            price >= ?';
    // Send the query to the database program and get all the rows back
    $stmt = $db->prepare($sql);
    $stmt->execute(array($input['min_price']));
    $dishes = $stmt->fetchAll();
    if (count($dishes) == 0) {
        print 'No dishes matched.';
    } else {
        print '<table>';
        print '<tr><th>Dish Name</th><th>Price</th><th>Spicy?</th></tr>';
        foreach ($dishes as $dish) {
            if ($dish->is_spicy == 1) {
                $spicy = 'Yes';
            } else {
                $spicy = 'No';
            }
        }
        printf(
            '<tr><td>%s</td><td>$%.02f</td><td>%s</td></tr>',
            htmlentities($dish->dish_name),
            $dish->price,
            $spicy
        );
        print '</table>';
    }
 }

 // The code relies on the FormHelper.php file discussed in Chapter 7. 
 // The price-form.php file referenced, which displays the form HTML, contains: ?>

 <form method="POST" action="<?= $form->encode($_SERVER['PHP_SELF']) ?>">
    <table>
        <?php if ($errors) { ?>
            <tr>
                <td>You need to correct the following errors:</td>
                <td>
                    <ul>
                        <?php foreach ($errors as $error) { ?>
                            <li><?= $form->encode($error) ?></li>
                        <?php } ?>
                    </ul>
                </td>
            <?php } ?>
        <tr>
            <td>Minimum Price:</td>
            <td><?= $form->input('text', ['name' => 'min_price']) ?></td>
        </tr>
        <tr>
            <td colspan="2" align="center">
                <?= $form->input('submit', [
                    'name' => 'search',
                    'value' => 'Search'
                ]) ?>
            </td>
        </tr>
    </table>
 </form><?php

 // Question-3

 // 3. Write a program that displays a form with a <select> menu of dish names. 
 // Create the dish names to display by retrieving them from the database. 
 // When the form is submitted, the program should print out all of the information in the table (ID, name, price, and spiciness) for the selected dish.

 // Answer-3

 // Load the form helper class
 require 'FormHelper.php';
 // Connect to the database
 try {
    $db = new PDO('sqlite:/tmp/restaurant.db');
 } catch (PDOException $e) {
    print "Can't connect: " . $e->getMessage();
    exit();
 }
 // Set up exceptions on DB errors
 $db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
 // Set up fetch mode: rows as objects
 $db->setAttribute(PDO::ATTR_DEFAULT_FETCH_MODE, PDO::FETCH_OBJ);
 // The main page logic:
 // - If the form is submitted, validate and then process or redisplay
 // - If it's not submitted, display
 if ($_SERVER['REQUEST_METHOD'] == 'POST') {
    // If validate_form() returns errors, pass them to show_form()
    list($errors, $input) = validate_form();
    if ($errors) {
        show_form($errors);
    } else {
        // The submitted data is valid, so process it
        process_form($input);
    }
 } else {
    // The form wasn't submitted, so display
    show_form();
 }

 function show_form2($errors = array())
 {
    global $db;
    // Set up the $form object with proper defaults
    $form = new FormHelper();
    // Retrieve the list of dish names to use from the database
    $sql = 'SELECT dish_id, dish_name FROM dishes ORDER BY dish_name';
    $stmt = $db->query($sql);
    $dishes = array();
    while ($row = $stmt->fetch()) {
        $dishes[$row->dish_id] = $row->dish_name;
    }
    // All the HTML and form display is in a separate file for clarity
    include 'dish-form.php';
 }

 function validate_form2()
 {
    $input = array();
    $errors = array();
    // As long as some dish_id value is submitted, we'll consider it OK.
    // If it doesn't match any dishes in the database, process_form()
    // can report that.
    if (isset($_POST['dish_id'])) {
        $input['dish_id'] = $_POST['dish_id'];
    } else {
        $errors[] = 'Please select a dish.';
    }
    return array($errors, $input);
 }

 function process_form2($input)
 {
    // Access the global variable $db inside this function
    global $db;
    // Build up the query
    $sql = 'SELECT dish_id, dish_name, price, is_spicy FROM dishes WHERE
    dish_id = ?';
    // Send the query to the database program and get all the rows back
    $stmt = $db->prepare($sql);
    $stmt->execute(array($input['dish_id']));
    $dish = $stmt->fetch();
    if (count($dish) == 0) {
        print 'No dishes matched.';
    } else {
        print '<table>';
        print '<tr><th>ID</th><th>Dish Name</th><th>Price</th>';
        print '<th>Spicy?</th></tr>';
        if ($dish->is_spicy == 1) {
            $spicy = 'Yes';
        } else {
            $spicy = 'No';
        }
        printf(
            '<tr><td>%d</td><td>%s</td><td>$%.02f</td><td>%s</td></tr>',
            $dish->dish_id,
            htmlentities($dish->dish_name),
            $dish->price,
            $spicy
        );
        print '</table>';
    }
 }

 // The code relies on the FormHelper.php file discussed in Chapter 7. 
 // The dish-form.php file referenced, which displays the form HTML, contains: ?>

 <form method="POST" action="<?= $form->encode($_SERVER['PHP_SELF']) ?>">
    <table>
        <?php if ($errors) { ?>
            <tr>
                <td>You need to correct the following errors:</td>
                <td>
                    <ul>
                        <?php foreach ($errors as $error) { ?>
                            <li><?= $form->encode($error) ?></li>
                        <?php } ?>
                    </ul>
                </td>
            <?php } ?>
        <tr>
            <td>Dish:</td>
            <td><?= $form->select($dishes, ['name' => 'dish_id']) ?></td>
        </tr>
        <tr>
            <td colspan="2" align="center">
                <?= $form->input('submit', [
                    'name' => 'info',
                    'value' => 'Get Dish Info'
                ]) ?>
            </td>
        </tr>
    </table>
    <?php

    // Question-4
    
    // 4. Create a new table that holds information about restaurant customers. 
    // The table should store the following information about each customer: customer ID, name, phone number, 
    // and the ID of the customer’s favorite dish. Write a program that displays a form for putting a new customer into the table. 
    // The part of the form for entering the customer’s favorite dish should be a <select> menu of dish names. 
    // The customer’s ID should be generated by your program, not entered in the form.
    
    // Answer-4
    
    // Load the form helper class
    require 'FormHelper.php';
    // Connect to the database
    try {
        $db = new PDO('sqlite:/tmp/restaurant.db');
    } catch (PDOException $e) {
        print "Can't connect: " . $e->getMessage();
        exit();
    }
    // Set up exceptions on DB errors
    $db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
    // Set up fetch mode: rows as objects
    $db->setAttribute(PDO::ATTR_DEFAULT_FETCH_MODE, PDO::FETCH_OBJ);
    // Put the list of dish IDs and names in a global array because
 // we'll need it in show_form() and validate_form()
    $dishes = array();
    $sql = 'SELECT dish_id, dish_name FROM dishes ORDER BY dish_name';
    $stmt = $db->query($sql);
    while ($row = $stmt->fetch()) {
        $dishes[$row->dish_id] = $row->dish_name;
    }
    // The main page logic:
 // - If the form is submitted, validate and then process or redisplay
 // - If it's not submitted, display
    if ($_SERVER['REQUEST_METHOD'] == 'POST') {
        // If validate_form() returns errors, pass them to show_form()
        list($errors, $input) = validate_form();
        if ($errors) {
            show_form($errors);
        } else {
            // The submitted data is valid, so process it
            process_form($input);
        }
    } else {
        // The form wasn't submitted, so display
        show_form();
    }
    function show_form3($errors = array())
    {
        global $db, $dishes;
        // Set up the $form object with proper defaults
        $form = new FormHelper();
        // All the HTML and form display is in a separate file for clarity
        include 'customer-form.php';
    }

    function validate_form3()
    {
        global $dishes;
        $input = array();
        $errors = array();
        // Make sure a dish_id valid is submitted and in $dishes.
        // As long as some dish_id value is submitted, we'll consider it OK.
        // If it doesn't match any dishes in the database, process_form()
        // can report that.
        $input['dish_id'] = $_POST['dish_id'] ?? '';
        if (!array_key_exists($input['dish_id'], $dishes)) {
            $errors[] = 'Please select a valid dish.';
        }
        // Name is required
        $input['name'] = trim($_POST['name'] ?? '');
        if (0 == strlen($input['name'])) {
            $errors[] = 'Please enter a name.';
        }
        // Phone number is required
        $input['phone'] = trim($_POST['phone'] ?? '');
        if (0 == strlen($input['phone'])) {
            $errors[] = 'Please enter a phone number.';
        } else {
            // Be US-centric and ensure that the phone number contains
            // at least 10 digits. Using ctype_digit() on each
            // character is not the most efficient way to do this,
            // but is logically straightforward and avoids
            // regular expressions.
            $digits = 0;
            for ($i = 0; $i < strlen($input['phone']); $i++) {
                if (ctype_digit($input['phone'][$i])) {
                    $digits++;
                }
            }
            if ($digits < 10) {
                $errors[] = 'Phone number needs at least ten digits.';
            }
        }
        return array($errors, $input);
    }

    function process_form4($input)
    {
        // Access the global variable $db inside this function
        global $db;
        // Build up the query. No need to specify customer_id because
        // the database will automatically assign a unique one.
        $sql = 'INSERT INTO customers (name,phone,favorite_dish_id) ' .
            'VALUES (?,?,?)';
        // Send the query to the database program and get all the rows back
        try {
            $stmt = $db->prepare($sql);
            $stmt->execute(array($input['name'], $input['phone'], $input['dish_id']));
            print '<p>Inserted new customer.</p>';
        } catch (Exception $e) {
            print "<p>Couldn't insert customer: {$e->getMessage()}.</p>";
        }
    }

    // The code relies on the FormHelper.php file discussed in Chapter 7. 
    // The customer-form.php file referenced, which displays the form HTML, contains: ?>

    <form method="POST" action="<?= $form->encode($_SERVER['PHP_SELF']) ?>">
        <table>
            <?php if ($errors) { ?>
                <tr>
                    <td>You need to correct the following errors:</td>
                    <td>
                        <ul>
                            <?php foreach ($errors as $error) { ?>
                                <li><?= $form->encode($error) ?></li>
                            <?php } ?>
                        </ul>
                    </td>
                <?php } ?>
            <tr>
            <tr>
                <td>Name:</td>
                <td><?= $form->input('text', ['name' => 'name']) ?>
                </td>
            </tr>
            <tr>
                <td>Phone Number:</td>
                <td><?= $form->input('text', ['name' => 'phone']) ?></td>
            </tr>
            <tr>
                <td>Favorite Dish:</td>
                <td><?= $form->select($dishes, ['name' => 'dish_id']) ?></td>
            </tr>
            <tr>
                <td colspan="2" align="center">
                    <?= $form->input('submit', ['name' => 'add', 'value' => 'Add Customer']) ?>
                </td>
            </tr>
        </table>
    </form>
	<?php
	// Chapter-8: Exercises

	// The following exercises use a database table called dishes with the following structure:
	// -- CREATE TABLE dishes (
	// -- dish_id INT,
	// -- dish_name VARCHAR(255),
	// -- price DECIMAL(4,2),
	// -- is_spicy INT
	// -- )
	// Here is some sample data to put into the dishes table:
	// -- INSERT INTO dishes VALUES (1,'Walnut Bun',1.00,0)
	// -- INSERT INTO dishes VALUES (2,'Cashew Nuts and White Mushrooms',4.95,0)
	// -- INSERT INTO dishes VALUES (3,'Dried Mulberries',3.00,0)
	// -- INSERT INTO dishes VALUES (4,'Eggplant with Chili Sauce',6.50,1)
	// -- INSERT INTO dishes VALUES (5,'Red Bean Bun',1.00,0)
	// -- INSERT INTO dishes VALUES (6,'General Tso''s Chicken',5.50,1)

	// Question-1

	// 1. Write a program that lists all of the dishes in the table, sorted by price.

	// Answer-1

	try {
	// Connect
	$db = new PDO('sqlite:/tmp/restaurant.db');
	// Set up exceptions on DB errors
	$db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
	$stmt = $db->query('SELECT * FROM dishes ORDER BY price');
	$dishes = $stmt->fetchAll();
	if (count($dishes) == 0) {
	$html = '<p>No dishes to display</p>';
	} else {
	$html = "<table>\n";
	$html .= "<tr><th>Dish Name</th><th>Price</th><th>Spicy?</th></tr>\n";
	foreach ($dishes as $dish) {
	$html .= '<tr><td>' .
	htmlentities($dish['dish_name']) . '</td><td>$' .
	sprintf('%.02f', $dish['price']) . '</td><td>' .
	($dish['is_spicy'] ? 'Yes' : 'No') . "</td></tr>\n";
	}
	$html .= "</table>";
	}
	} catch (PDOException $e) {
	$html = "Can't show dishes: " . $e->getMessage();
	}
	print $html;

	// Question-2

	// 2. Write a program that displays a form asking for a price. When the form is submitted,
	// the program should print out the names and prices of the dishes whose price is at least the submitted price.
	// Don’t retrieve from the database any rows or columns that aren’t printed in the table.

	// Answer-2

	// Load the form helper class
	require 'FormHelper.php';
	// Connect to the database
	try {
	$db = new PDO('sqlite:/tmp/restaurant.db');
	} catch (PDOException $e) {
	print "Can't connect: " . $e->getMessage();
	exit();
	}
	// Set up exceptions on DB errors
	$db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
	// Set up fetch mode: rows as objects
	$db->setAttribute(PDO::ATTR_DEFAULT_FETCH_MODE, PDO::FETCH_OBJ);
	// The main page logic:
	// - If the form is submitted, validate and then process or redisplay
	// - If it's not submitted, display
	if ($_SERVER['REQUEST_METHOD'] == 'POST') {
	// If validate_form() returns errors, pass them to show_form()
	list($errors, $input) = validate_form();
	if ($errors) {
	show_form($errors);
	} else {
	// The submitted data is valid, so process it
	process_form($input);
	}
	} else {
	// The form wasn't submitted, so display
	show_form();
	}
	function show_form($errors = array())
	{
	// Set up the $form object with proper defaults
	$form = new FormHelper();
	// All the HTML and form display is in a separate file for clarity
	include 'price-form.php';
	}

	function validate_form()
	{
	$input = array();
	$errors = array();
	// Minimum price must be a valid floating-point number
	$input['min_price'] = filter_input(
	INPUT_POST,
	'min_price',
	FILTER_VALIDATE_FLOAT
	);
	if ($input['min_price'] === null \|\| $input['min_price'] === false) {
	$errors[] = 'Please enter a valid minimum price.';
	}
	return array($errors, $input);
	}

	function process_form($input)
	{
	// Access the global variable $db inside this function
	global $db;
	// Build up the query
	$sql = 'SELECT dish_name, price, is_spicy FROM dishes WHERE
	price >= ?';
	// Send the query to the database program and get all the rows back
	$stmt = $db->prepare($sql);
	$stmt->execute(array($input['min_price']));
	$dishes = $stmt->fetchAll();
	if (count($dishes) == 0) {
	print 'No dishes matched.';
	} else {
	print '<table>';
	print '<tr><th>Dish Name</th><th>Price</th><th>Spicy?</th></tr>';
	foreach ($dishes as $dish) {
	if ($dish->is_spicy == 1) {
	$spicy = 'Yes';
	} else {
	$spicy = 'No';
	}
	}
	printf(
	'<tr><td>%s</td><td>$%.02f</td><td>%s</td></tr>',
	htmlentities($dish->dish_name),
	$dish->price,
	$spicy
	);
	print '</table>';
	}
	}

	// The code relies on the FormHelper.php file discussed in Chapter 7.
	// The price-form.php file referenced, which displays the form HTML, contains: ?>

	<form method="POST" action="<?= $form->encode($_SERVER['PHP_SELF']) ?>">
	<table>
	<?php if ($errors) { ?>
	<tr>
	<td>You need to correct the following errors:</td>
	<td>
	<ul>
	<?php foreach ($errors as $error) { ?>
	<li><?= $form->encode($error) ?></li>
	<?php } ?>
	</ul>
	</td>
	<?php } ?>
	<tr>
	<td>Minimum Price:</td>
	<td><?= $form->input('text', ['name' => 'min_price']) ?></td>
	</tr>
	<tr>
	<td colspan="2" align="center">
	<?= $form->input('submit', [
	'name' => 'search',
	'value' => 'Search'
	]) ?>
	</td>
	</tr>
	</table>
	</form><?php

	// Question-3

	// 3. Write a program that displays a form with a <select> menu of dish names.
	// Create the dish names to display by retrieving them from the database.
	// When the form is submitted, the program should print out all of the information in the table (ID, name, price, and spiciness) for the selected dish.

	// Answer-3

	// Load the form helper class
	require 'FormHelper.php';
	// Connect to the database
	try {
	$db = new PDO('sqlite:/tmp/restaurant.db');
	} catch (PDOException $e) {
	print "Can't connect: " . $e->getMessage();
	exit();
	}
	// Set up exceptions on DB errors
	$db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
	// Set up fetch mode: rows as objects
	$db->setAttribute(PDO::ATTR_DEFAULT_FETCH_MODE, PDO::FETCH_OBJ);
	// The main page logic:
	// - If the form is submitted, validate and then process or redisplay
	// - If it's not submitted, display
	if ($_SERVER['REQUEST_METHOD'] == 'POST') {
	// If validate_form() returns errors, pass them to show_form()
	list($errors, $input) = validate_form();
	if ($errors) {
	show_form($errors);
	} else {
	// The submitted data is valid, so process it
	process_form($input);
	}
	} else {
	// The form wasn't submitted, so display
	show_form();
	}

	function show_form2($errors = array())
	{
	global $db;
	// Set up the $form object with proper defaults
	$form = new FormHelper();
	// Retrieve the list of dish names to use from the database
	$sql = 'SELECT dish_id, dish_name FROM dishes ORDER BY dish_name';
	$stmt = $db->query($sql);
	$dishes = array();
	while ($row = $stmt->fetch()) {
	$dishes[$row->dish_id] = $row->dish_name;
	}
	// All the HTML and form display is in a separate file for clarity
	include 'dish-form.php';
	}

	function validate_form2()
	{
	$input = array();
	$errors = array();
	// As long as some dish_id value is submitted, we'll consider it OK.
	// If it doesn't match any dishes in the database, process_form()
	// can report that.
	if (isset($_POST['dish_id'])) {
	$input['dish_id'] = $_POST['dish_id'];
	} else {
	$errors[] = 'Please select a dish.';
	}
	return array($errors, $input);
	}

	function process_form2($input)
	{
	// Access the global variable $db inside this function
	global $db;
	// Build up the query
	$sql = 'SELECT dish_id, dish_name, price, is_spicy FROM dishes WHERE
	dish_id = ?';
	// Send the query to the database program and get all the rows back
	$stmt = $db->prepare($sql);
	$stmt->execute(array($input['dish_id']));
	$dish = $stmt->fetch();
	if (count($dish) == 0) {
	print 'No dishes matched.';
	} else {
	print '<table>';
	print '<tr><th>ID</th><th>Dish Name</th><th>Price</th>';
	print '<th>Spicy?</th></tr>';
	if ($dish->is_spicy == 1) {
	$spicy = 'Yes';
	} else {
	$spicy = 'No';
	}
	printf(
	'<tr><td>%d</td><td>%s</td><td>$%.02f</td><td>%s</td></tr>',
	$dish->dish_id,
	htmlentities($dish->dish_name),
	$dish->price,
	$spicy
	);
	print '</table>';
	}
	}

	// The code relies on the FormHelper.php file discussed in Chapter 7.
	// The dish-form.php file referenced, which displays the form HTML, contains: ?>

	<form method="POST" action="<?= $form->encode($_SERVER['PHP_SELF']) ?>">
	<table>
	<?php if ($errors) { ?>
	<tr>
	<td>You need to correct the following errors:</td>
	<td>
	<ul>
	<?php foreach ($errors as $error) { ?>
	<li><?= $form->encode($error) ?></li>
	<?php } ?>
	</ul>
	</td>
	<?php } ?>
	<tr>
	<td>Dish:</td>
	<td><?= $form->select($dishes, ['name' => 'dish_id']) ?></td>
	</tr>
	<tr>
	<td colspan="2" align="center">
	<?= $form->input('submit', [
	'name' => 'info',
	'value' => 'Get Dish Info'
	]) ?>
	</td>
	</tr>
	</table>
	<?php

	// Question-4

	// 4. Create a new table that holds information about restaurant customers.
	// The table should store the following information about each customer: customer ID, name, phone number,
	// and the ID of the customer’s favorite dish. Write a program that displays a form for putting a new customer into the table.
	// The part of the form for entering the customer’s favorite dish should be a <select> menu of dish names.
	// The customer’s ID should be generated by your program, not entered in the form.

	// Answer-4

	// Load the form helper class
	require 'FormHelper.php';
	// Connect to the database
	try {
	$db = new PDO('sqlite:/tmp/restaurant.db');
	} catch (PDOException $e) {
	print "Can't connect: " . $e->getMessage();
	exit();
	}
	// Set up exceptions on DB errors
	$db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
	// Set up fetch mode: rows as objects
	$db->setAttribute(PDO::ATTR_DEFAULT_FETCH_MODE, PDO::FETCH_OBJ);
	// Put the list of dish IDs and names in a global array because
	// we'll need it in show_form() and validate_form()
	$dishes = array();
	$sql = 'SELECT dish_id, dish_name FROM dishes ORDER BY dish_name';
	$stmt = $db->query($sql);
	while ($row = $stmt->fetch()) {
	$dishes[$row->dish_id] = $row->dish_name;
	}
	// The main page logic:
	// - If the form is submitted, validate and then process or redisplay
	// - If it's not submitted, display
	if ($_SERVER['REQUEST_METHOD'] == 'POST') {
	// If validate_form() returns errors, pass them to show_form()
	list($errors, $input) = validate_form();
	if ($errors) {
	show_form($errors);
	} else {
	// The submitted data is valid, so process it
	process_form($input);
	}
	} else {
	// The form wasn't submitted, so display
	show_form();
	}
	function show_form3($errors = array())
	{
	global $db, $dishes;
	// Set up the $form object with proper defaults
	$form = new FormHelper();
	// All the HTML and form display is in a separate file for clarity
	include 'customer-form.php';
	}

	function validate_form3()
	{
	global $dishes;
	$input = array();
	$errors = array();
	// Make sure a dish_id valid is submitted and in $dishes.
	// As long as some dish_id value is submitted, we'll consider it OK.
	// If it doesn't match any dishes in the database, process_form()
	// can report that.
	$input['dish_id'] = $_POST['dish_id'] ?? '';
	if (!array_key_exists($input['dish_id'], $dishes)) {
	$errors[] = 'Please select a valid dish.';
	}
	// Name is required
	$input['name'] = trim($_POST['name'] ?? '');
	if (0 == strlen($input['name'])) {
	$errors[] = 'Please enter a name.';
	}
	// Phone number is required
	$input['phone'] = trim($_POST['phone'] ?? '');
	if (0 == strlen($input['phone'])) {
	$errors[] = 'Please enter a phone number.';
	} else {
	// Be US-centric and ensure that the phone number contains
	// at least 10 digits. Using ctype_digit() on each
	// character is not the most efficient way to do this,
	// but is logically straightforward and avoids
	// regular expressions.
	$digits = 0;
	for ($i = 0; $i < strlen($input['phone']); $i++) {
	if (ctype_digit($input['phone'][$i])) {
	$digits++;
	}
	}
	if ($digits < 10) {
	$errors[] = 'Phone number needs at least ten digits.';
	}
	}
	return array($errors, $input);
	}

	function process_form4($input)
	{
	// Access the global variable $db inside this function
	global $db;
	// Build up the query. No need to specify customer_id because
	// the database will automatically assign a unique one.
	$sql = 'INSERT INTO customers (name,phone,favorite_dish_id) ' .
	'VALUES (?,?,?)';
	// Send the query to the database program and get all the rows back
	try {
	$stmt = $db->prepare($sql);
	$stmt->execute(array($input['name'], $input['phone'], $input['dish_id']));
	print '<p>Inserted new customer.</p>';
	} catch (Exception $e) {
	print "<p>Couldn't insert customer: {$e->getMessage()}.</p>";
	}
	}

	// The code relies on the FormHelper.php file discussed in Chapter 7.
	// The customer-form.php file referenced, which displays the form HTML, contains: ?>

	<form method="POST" action="<?= $form->encode($_SERVER['PHP_SELF']) ?>">
	<table>
	<?php if ($errors) { ?>
	<tr>
	<td>You need to correct the following errors:</td>
	<td>
	<ul>
	<?php foreach ($errors as $error) { ?>
	<li><?= $form->encode($error) ?></li>
	<?php } ?>
	</ul>
	</td>
	<?php } ?>
	<tr>
	<tr>
	<td>Name:</td>
	<td><?= $form->input('text', ['name' => 'name']) ?>
	</td>
	</tr>
	<tr>
	<td>Phone Number:</td>
	<td><?= $form->input('text', ['name' => 'phone']) ?></td>
	</tr>
	<tr>
	<td>Favorite Dish:</td>
	<td><?= $form->select($dishes, ['name' => 'dish_id']) ?></td>
	</tr>
	<tr>
	<td colspan="2" align="center">
	<?= $form->input('submit', ['name' => 'add', 'value' => 'Add Customer']) ?>
	</td>
	</tr>
	</table>
	</form>