Como criar um blog no banco de dados PHP e MySQL - design de banco de dados

O banco de dados

+----+-----------+--------------+------------+
|     field      |     type     | specs      |
+----+-----------+--------------+------------+
|  id            | INT(11)      |            |
|  user_id       | INT(11)      |            |
|  title         | VARCHAR(255) |            |
|  slug          | VARCHAR(255) | UNIQUE     |
|  views         | INT(11)      |            |
|  image         | VARCHAR(255) |            |
|  body          | TEXT         |            |
|  published     | boolean      |            |
|  created_at    | TIMESTAMP    |            |
|  updated_at    | TIMESTAMP    |            |
+----------------+--------------+------------+

+----+-----------+------------------------+------------+
|     field      |     type               | specs      |
+----+-----------+------------------------+------------+
|  id            | INT(11)                |            |
|  username      | VARCHAR(255)           | UNIQUE     |
|  email         | VARCHAR(255)           | UNIQUE     |
|  role          | ENUM("Admin","Author") |            |
|  password      | VARCHAR(255)           |            |
|  created_at    | TIMESTAMP              |            |
|  updated_at    | TIMESTAMP              |            |
+----------------+--------------+---------+------------+

CREATE TABLE `users` (
  `id` int(11) AUTO_INCREMENT PRIMARY KEY NOT NULL,
  `username` varchar(255) NOT NULL,
  `email` varchar(255) NOT NULL,
  `role` enum('Author','Admin') DEFAULT NULL,
  `password` varchar(255) NOT NULL,
  `created_at` timestamp NULL DEFAULT CURRENT_TIMESTAMP,
  `updated_at` timestamp NULL DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

CREATE TABLE `posts` (
 `id` int(11) NOT NULL AUTO_INCREMENT PRIMARY KEY,
 `user_id` int(11) DEFAULT NULL,
 `title` varchar(255) NOT NULL,
 `slug` varchar(255) NOT NULL UNIQUE,
 `views` int(11) NOT NULL DEFAULT '0',
 `image` varchar(255) NOT NULL,
 `body` text NOT NULL,
 `published` tinyint(1) NOT NULL,
 `created_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
 `updated_at` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00',
  FOREIGN KEY (`user_id`) REFERENCES `users` (`id`) ON DELETE NO ACTION ON UPDATE NO ACTION
) ENGINE=InnoDB DEFAULT CHARSET=latin1

INSERT INTO `users` (`id`, `username`, `email`, `role`, `password`, `created_at`, `updated_at`) VALUES
(1, 'Awa', '[email protected]', 'Admin', 'mypassword', '2018-01-08 12:52:58', '2018-01-08 12:52:58')

INSERT INTO `posts` (`id`, `user_id`, `title`, `slug`, `views`, `image`, `body`, `published`, `created_at`, `updated_at`) VALUES
(1, 1, '5 Habits that can improve your life', '5-habits-that-can-improve-your-life', 0, 'banner.jpg', 'Read every day', 1, '2018-02-03 07:58:02', '2018-02-01 19:14:31'),
(2, 1, 'Second post on LifeBlog', 'second-post-on-lifeblog', 0, 'banner.jpg', 'This is the body of the second post on this site', 0, '2018-02-02 11:40:14', '2018-02-01 13:04:36')

<?php 
	session_start();
	// connect to database
	$conn = mysqli_connect("localhost", "root", "", "complete-blog-php");

	if (!$conn) {
		die("Error connecting to database: " . mysqli_connect_error());
	}
    // define global constants
	define ('ROOT_PATH', realpath(dirname(__FILE__)));
	define('BASE_URL', 'http://localhost/complete-blog-php/');
?>

<?php 
/* * * * * * * * * * * * * * *
* Returns all published posts
* * * * * * * * * * * * * * */
function getPublishedPosts() {
	// use global $conn object in function
	global $conn;
	$sql = "SELECT * FROM posts WHERE published=true";
	$result = mysqli_query($conn, $sql);

	// fetch all posts as an associative array called $posts
	$posts = mysqli_fetch_all($result, MYSQLI_ASSOC);

	return $posts;
}

// more functions to come here ...
?>

<!-- config.php should be here as the first include  -->

<?php require_once( ROOT_PATH . '/includes/public_functions.php') ?>

<!-- Retrieve all posts from database  -->
<?php $posts = getPublishedPosts(); ?>

<hr>
<!-- more content still to come here ... -->

<!-- Add this ... -->
<?php foreach ($posts as $post): ?>
	<div class="post" style="margin-left: 0px;">
		<img src="<?php echo BASE_URL . '/static/images/' . $post['image']; ?>" class="post_image" alt="">
		<a href="single_post.php?post-slug=<?php echo $post['slug']; ?>">
			<div class="post_info">
				<h3><?php echo $post['title'] ?></h3>
				<div class="info">
					<span><?php echo date("F j, Y ", strtotime($post["created_at"])); ?></span>
					<span class="read_more">Read more...</span>
				</div>
			</div>
		</a>
	</div>
<?php endforeach ?>

/* CONTENT */
.content {
	margin: 5px auto;
	border-radius: 5px;
	min-height: 400px;
}
.content:after {
	content: "";
	display: block;
	clear: both;
}
.content .content-title {
	margin: 10px 0px;
	color: #374447;
	font-family: 'Averia Serif Libre', cursive;
}
.content .post {
	width: 335px;
	margin: 9px;
	min-height: 320px;
	float: left;
	border-radius: 2px;
	border: 1px solid #b3b3b3;
	position: relative;
}
.content .post .category {
	margin-top: 0px;
	padding: 3px 8px;
	color: #374447;
	background: white;
	display: inline-block;
	border-radius: 2px;
	border: 1px solid #374447;
	box-shadow: 3px 2px 2px;
	position: absolute;
	left: 5px; top: 5px;
	z-index: 3;
}
.content .post .category:hover {
	box-shadow: 3px 2px 2px;
	color: white;
	background: #374447;
	transition: .4s;
	opacity: 1;
}
.content .post .post_image {
	height: 260px;
	width: 100%;
	background-size: 100%;
}
.content .post .post_image {
	width: 100%;
	height: 260px;
}
.content .post .post_info {
	height: 100%;
	padding: 0px 5px;
	font-weight: 200;
    font-family: 'Noto Serif', serif;
}
.content .post .post_info {
	color: #222;
}
.content .post .post_info span {
	color: #A6A6A6;
	font-style: italic;
}
.content .post .post_info span.read_more {
	position: absolute;
	right: 5px; bottom: 5px;
}

+----+-----------+------------------------+------------+
|     field      |     type               | specs      |
+----+-----------+------------------------+------------+
|  id            | INT(11)                |            |
|  name          | VARCHAR(255)           |            |
|  slug          | VARCHAR(255)           | UNIQUE     |
+----------------+--------------+---------+------------+

+----+-----------+------------------------+------------+
|     field      |     type               | specs      |
+----+-----------+------------------------+------------+
|  id            | INT(11)                |            |
|  post_id       | INT(11)                |  UNIQUE    |
|  topic_id      | INT(11)                |            |
+----------------+--------------+---------+------------+

INSERT INTO `topics` (`id`, `name`, `slug`) VALUES
(1, 'Inspiration', 'inspiration'),
(2, 'Motivation', 'motivation'),
(3, 'Diary', 'diary')

INSERT INTO `post_topic` (`id`, `post_id`, `topic_id`) VALUES
(1, 1, 1),
(2, 2, 2)

<?php 
/* * * * * * * * * * * * * * *
* Returns all published posts
* * * * * * * * * * * * * * */
function getPublishedPosts() {
	// use global $conn object in function
	global $conn;
	$sql = "SELECT * FROM posts WHERE published=true";
	$result = mysqli_query($conn, $sql);
	// fetch all posts as an associative array called $posts
	$posts = mysqli_fetch_all($result, MYSQLI_ASSOC);

	$final_posts = array();
	foreach ($posts as $post) {
		$post['topic'] = getPostTopic($post['id']); 
		array_push($final_posts, $post);
	}
	return $final_posts;
}
/* * * * * * * * * * * * * * *
* Receives a post id and
* Returns topic of the post
* * * * * * * * * * * * * * */
function getPostTopic($post_id){
	global $conn;
	$sql = "SELECT * FROM topics WHERE id=
			(SELECT topic_id FROM post_topic WHERE post_id=$post_id) LIMIT 1";
	$result = mysqli_query($conn, $sql);
	$topic = mysqli_fetch_assoc($result);
	return $topic;
}
?>

<?php foreach ($posts as $post): ?>
	<div class="post" style="margin-left: 0px;">
		<img src="<?php echo BASE_URL . '/static/images/' . $post['image']; ?>" class="post_image" alt="">
        <!-- Added this if statement... -->
		<?php if (isset($post['topic']['name'])): ?>
			<a 
				href="<?php echo BASE_URL . 'filtered_posts.php?topic=' . $post['topic']['id'] ?>"
				class="btn category">
				<?php echo $post['topic']['name'] ?>
			</a>
		<?php endif ?>

		<a href="single_post.php?post-slug=<?php echo $post['slug']; ?>">
			<div class="post_info">
				<h3><?php echo $post['title'] ?></h3>
				<div class="info">
					<span><?php echo date("F j, Y ", strtotime($post["created_at"])); ?></span>
					<span class="read_more">Read more...</span>
				</div>
			</div>
		</a>
	</div>
<?php endforeach ?>

/* * * * * * * * * * * * * * * *
* Returns all posts under a topic
* * * * * * * * * * * * * * * * */
function getPublishedPostsByTopic($topic_id) {
	global $conn;
	$sql = "SELECT * FROM posts ps 
			WHERE ps.id IN 
			(SELECT pt.post_id FROM post_topic pt 
				WHERE pt.topic_id=$topic_id GROUP BY pt.post_id 
				HAVING COUNT(1) = 1)";
	$result = mysqli_query($conn, $sql);
	// fetch all posts as an associative array called $posts
	$posts = mysqli_fetch_all($result, MYSQLI_ASSOC);

	$final_posts = array();
	foreach ($posts as $post) {
		$post['topic'] = getPostTopic($post['id']); 
		array_push($final_posts, $post);
	}
	return $final_posts;
}
/* * * * * * * * * * * * * * * *
* Returns topic name by topic id
* * * * * * * * * * * * * * * * */
function getTopicNameById($id)
{
	global $conn;
	$sql = "SELECT name FROM topics WHERE id=$id";
	$result = mysqli_query($conn, $sql);
	$topic = mysqli_fetch_assoc($result);
	return $topic['name'];
}

<?php include('config.php'); ?>
<?php include('includes/public_functions.php'); ?>
<?php include('includes/head_section.php'); ?>
<?php 
	// Get posts under a particular topic
	if (isset($_GET['topic'])) {
		$topic_id = $_GET['topic'];
		$posts = getPublishedPostsByTopic($topic_id);
	}
?>
	<title>LifeBlog | Home </title>
</head>
<body>
<div class="container">
<!-- Navbar -->
	<?php include( ROOT_PATH . '/includes/navbar.php'); ?>
<!-- // Navbar -->
<!-- content -->
<div class="content">
	<h2 class="content-title">
		Articles on <u><?php echo getTopicNameById($topic_id); ?></u>
	</h2>
	<hr>
	<?php foreach ($posts as $post): ?>
		<div class="post" style="margin-left: 0px;">
			<img src="<?php echo BASE_URL . '/static/images/' . $post['image']; ?>" class="post_image" alt="">
			<a href="single_post.php?post-slug=<?php echo $post['slug']; ?>">
				<div class="post_info">
					<h3><?php echo $post['title'] ?></h3>
					<div class="info">
						<span><?php echo date("F j, Y ", strtotime($post["created_at"])); ?></span>
						<span class="read_more">Read more...</span>
					</div>
				</div>
			</a>
		</div>
	<?php endforeach ?>
</div>
<!-- // content -->
</div>
<!-- // container -->

<!-- Footer -->
	<?php include( ROOT_PATH . '/includes/footer.php'); ?>
<!-- // Footer -->

/* * * * * * * * * * * * * * *
* Returns a single post
* * * * * * * * * * * * * * */
function getPost($slug){
	global $conn;
	// Get single post slug
	$post_slug = $_GET['post-slug'];
	$sql = "SELECT * FROM posts WHERE slug='$post_slug' AND published=true";
	$result = mysqli_query($conn, $sql);

	// fetch query results as associative array.
	$post = mysqli_fetch_assoc($result);
	if ($post) {
		// get the topic to which this post belongs
		$post['topic'] = getPostTopic($post['id']);
	}
	return $post;
}
/* * * * * * * * * * * *
*  Returns all topics
* * * * * * * * * * * * */
function getAllTopics()
{
	global $conn;
	$sql = "SELECT * FROM topics";
	$result = mysqli_query($conn, $sql);
	$topics = mysqli_fetch_all($result, MYSQLI_ASSOC);
	return $topics;
}

<?php  include('config.php'); ?>
<?php  include('includes/public_functions.php'); ?>
<?php 
	if (isset($_GET['post-slug'])) {
		$post = getPost($_GET['post-slug']);
	}
	$topics = getAllTopics();
?>
<?php include('includes/head_section.php'); ?>
<title> <?php echo $post['title'] ?> | LifeBlog</title>
</head>
<body>
<div class="container">
	<!-- Navbar -->
		<?php include( ROOT_PATH . '/includes/navbar.php'); ?>
	<!-- // Navbar -->
	
	<div class="content" >
		<!-- Page wrapper -->
		<div class="post-wrapper">
			<!-- full post div -->
			<div class="full-post-div">
			<?php if ($post['published'] == false): ?>
				<h2 class="post-title">Sorry... This post has not been published</h2>
			<?php else: ?>
				<h2 class="post-title"><?php echo $post['title']; ?></h2>
				<div class="post-body-div">
					<?php echo html_entity_decode($post['body']); ?>
				</div>
			<?php endif ?>
			</div>
			<!-- // full post div -->
			
			<!-- comments section -->
			<!--  coming soon ...  -->
		</div>
		<!-- // Page wrapper -->

		<!-- post sidebar -->
		<div class="post-sidebar">
			<div class="card">
				<div class="card-header">
					<h2>Topics</h2>
				</div>
				<div class="card-content">
					<?php foreach ($topics as $topic): ?>
						<a 
							href="<?php echo BASE_URL . 'filtered_posts.php?topic=' . $topic['id'] ?>">
							<?php echo $topic['name']; ?>
						</a> 
					<?php endforeach ?>
				</div>
			</div>
		</div>
		<!-- // post sidebar -->
	</div>
</div>
<!-- // content -->

<?php include( ROOT_PATH . '/includes/footer.php'); ?>

/* * * * * * * * *
* SINGLE PAGE 
* * * * * * * * */
.content .post-wrapper {
	width: 70%;
	float: left;
	min-height: 250px;
}
.full-post-div {
	min-height: 300px;
	padding: 20px;
	border: 1px solid #e4e1e1;
	border-radius: 2px;
}
.full-post-div h2.post-title {
	margin: 10px auto 20px;
	text-align: center;
}
.post-body-div {
	font-family: 'Noto Serif', serif;
	font-size: 1.2em;
}
.post-body-div p {
	margin:20px 0px;
}
.post-sidebar {
	width: 24%;
	float: left;
	margin-left: 5px;
	min-height: 400px;
}
.content .post-comments {
	margin-top: 25px;
	border-radius: 2px;
	border-top: 1px solid #e4e1e1;
	padding: 10px;
}
.post-sidebar .card {
	width: 95%;
	margin: 10px auto;
	border: 1px solid #e4e1e1;
	border-radius: 10px 10px 0px 0px;
}
.post-sidebar .card .card-header {
	padding: 10px;
	text-align: center;
	border-radius: 3px 3px 0px 0px;
	background: #3E606F;
}
.post-sidebar .card .card-header h2 {
	color: white;
}
.post-sidebar .card .card-content a {
	display: block;
	box-sizing: border-box;
	padding: 8px 10px;
	border-bottom: 1px solid #e4e1e1;
	color: #444;
}
.post-sidebar .card .card-content a:hover {
	padding-left: 20px;
	background: #F9F9F9;
	transition: 0.1s;
}

Registro e login do usuário

<?php  include('config.php'); ?>
<!-- Source code for handling registration and login -->
<?php  include('includes/registration_login.php'); ?>

<?php include('includes/head_section.php'); ?>

<title>LifeBlog | Sign up </title>
</head>
<body>
<div class="container">
	<!-- Navbar -->
		<?php include( ROOT_PATH . '/includes/navbar.php'); ?>
	<!-- // Navbar -->

	<div style="width: 40%; margin: 20px auto;">
		<form method="post" action="register.php" >
			<h2>Register on LifeBlog</h2>
			<?php include(ROOT_PATH . '/includes/errors.php') ?>
			<input  type="text" name="username" value="<?php echo $username; ?>"  placeholder="Username">
			<input type="email" name="email" value="<?php echo $email ?>" placeholder="Email">
			<input type="password" name="password_1" placeholder="Password">
			<input type="password" name="password_2" placeholder="Password confirmation">
			<button type="submit" class="btn" name="reg_user">Register</button>
			<p>
				Already a member? <a href="login.php">Sign in</a>
			</p>
		</form>
	</div>
</div>
<!-- // container -->
<!-- Footer -->
	<?php include( ROOT_PATH . '/includes/footer.php'); ?>
<!-- // Footer -->

<?php  include('config.php'); ?>
<?php  include('includes/registration_login.php'); ?>
<?php  include('includes/head_section.php'); ?>
	<title>LifeBlog | Sign in </title>
</head>
<body>
<div class="container">
	<!-- Navbar -->
	<?php include( ROOT_PATH . '/includes/navbar.php'); ?>
	<!-- // Navbar -->

	<div style="width: 40%; margin: 20px auto;">
		<form method="post" action="login.php" >
			<h2>Login</h2>
			<?php include(ROOT_PATH . '/includes/errors.php') ?>
			<input type="text" name="username" value="<?php echo $username; ?>" value="" placeholder="Username">
			<input type="password" name="password" placeholder="Password">
			<button type="submit" class="btn" name="login_btn">Login</button>
			<p>
				Not yet a member? <a href="register.php">Sign up</a>
			</p>
		</form>
	</div>
</div>
<!-- // container -->

<!-- Footer -->
	<?php include( ROOT_PATH . '/includes/footer.php'); ?>
<!-- // Footer -->

<?php 
	// variable declaration
	$username = "";
	$email    = "";
	$errors = array(); 

	// REGISTER USER
	if (isset($_POST['reg_user'])) {
		// receive all input values from the form
		$username = esc($_POST['username']);
		$email = esc($_POST['email']);
		$password_1 = esc($_POST['password_1']);
		$password_2 = esc($_POST['password_2']);

		// form validation: ensure that the form is correctly filled
		if (empty($username)) {  array_push($errors, "Uhmm...We gonna need your username"); }
		if (empty($email)) { array_push($errors, "Oops.. Email is missing"); }
		if (empty($password_1)) { array_push($errors, "uh-oh you forgot the password"); }
		if ($password_1 != $password_2) { array_push($errors, "The two passwords do not match");}

		// Ensure that no user is registered twice. 
		// the email and usernames should be unique
		$user_check_query = "SELECT * FROM users WHERE username='$username' 
								OR email='$email' LIMIT 1";

		$result = mysqli_query($conn, $user_check_query);
		$user = mysqli_fetch_assoc($result);

		if ($user) { // if user exists
			if ($user['username'] === $username) {
			  array_push($errors, "Username already exists");
			}
			if ($user['email'] === $email) {
			  array_push($errors, "Email already exists");
			}
		}
		// register user if there are no errors in the form
		if (count($errors) == 0) {
			$password = md5($password_1);//encrypt the password before saving in the database
			$query = "INSERT INTO users (username, email, password, created_at, updated_at) 
					  VALUES('$username', '$email', '$password', now(), now())";
			mysqli_query($conn, $query);

			// get id of created user
			$reg_user_id = mysqli_insert_id($conn); 

			// put logged in user into session array
			$_SESSION['user'] = getUserById($reg_user_id);

			// if user is admin, redirect to admin area
			if ( in_array($_SESSION['user']['role'], ["Admin", "Author"])) {
				$_SESSION['message'] = "You are now logged in";
				// redirect to admin area
				header('location: ' . BASE_URL . 'admin/dashboard.php');
				exit(0);
			} else {
				$_SESSION['message'] = "You are now logged in";
				// redirect to public area
				header('location: index.php');				
				exit(0);
			}
		}
	}

	// LOG USER IN
	if (isset($_POST['login_btn'])) {
		$username = esc($_POST['username']);
		$password = esc($_POST['password']);

		if (empty($username)) { array_push($errors, "Username required"); }
		if (empty($password)) { array_push($errors, "Password required"); }
		if (empty($errors)) {
			$password = md5($password); // encrypt password
			$sql = "SELECT * FROM users WHERE username='$username' and password='$password' LIMIT 1";

			$result = mysqli_query($conn, $sql);
			if (mysqli_num_rows($result) > 0) {
				// get id of created user
				$reg_user_id = mysqli_fetch_assoc($result)['id']; 

				// put logged in user into session array
				$_SESSION['user'] = getUserById($reg_user_id); 

				// if user is admin, redirect to admin area
				if ( in_array($_SESSION['user']['role'], ["Admin", "Author"])) {
					$_SESSION['message'] = "You are now logged in";
					// redirect to admin area
					header('location: ' . BASE_URL . '/admin/dashboard.php');
					exit(0);
				} else {
					$_SESSION['message'] = "You are now logged in";
					// redirect to public area
					header('location: index.php');				
					exit(0);
				}
			} else {
				array_push($errors, 'Wrong credentials');
			}
		}
	}
	// escape value from form
	function esc(String $value)
	{	
		// bring the global db connect object into function
		global $conn;

		$val = trim($value); // remove empty space sorrounding string
		$val = mysqli_real_escape_string($conn, $value);

		return $val;
	}
	// Get user info from user id
	function getUserById($id)
	{
		global $conn;
		$sql = "SELECT * FROM users WHERE id=$id LIMIT 1";

		$result = mysqli_query($conn, $sql);
		$user = mysqli_fetch_assoc($result);

		// returns user in an array format: 
		// ['id'=>1 'username' => 'Awa', 'email'=>'[email protected]', 'password'=> 'mypass']
		return $user; 
	}
?>

<?php if (count($errors) > 0) : ?>
  <div class="message error validation_errors" >
  	<?php foreach ($errors as $error) : ?>
  	  <p><?php echo $error ?></p>
  	<?php endforeach ?>
  </div>
<?php endif ?>

/* NOTIFICATION MESSAGES */
.message {
	width: 100%; 
	margin: 0px auto; 
	padding: 10px 0px; 
	color: #3c763d; 
	background: #dff0d8; 
	border: 1px solid #3c763d;
	border-radius: 5px; 
	text-align: center;
}
.error {
	color: #a94442; 
	background: #f2dede; 
	border: 1px solid #a94442; 
	margin-bottom: 20px;
}
.validation_errors p {
	text-align: left;
	margin-left: 10px;
}
.logged_in_info {
	text-align: right; 
	padding: 10px;
}

<?php 
	session_start();
	session_unset($_SESSION['user']);
	session_destroy();
	header('location: index.php');
?>

<?php if (isset($_SESSION['user']['username'])) { ?>
	<div class="logged_in_info">
		<span>welcome <?php echo $_SESSION['user']['username'] ?></span>
		|
		<span><a href="logout.php">logout</a></span>
	</div>
<?php }else{ ?>
	<div class="banner">
		<div class="welcome_msg">
			<h1>Today's Inspiration</h1>
			<p> 
			    One day your life <br> 
			    will flash before your eyes. <br> 
			    Make sure it's worth watching. <br>
				<span>~ Gerard Way</span>
			</p>
			<a href="register.php" class="btn">Join us!</a>
		</div>

		<div class="login_div">
			<form action="<?php echo BASE_URL . 'index.php'; ?>" method="post" >
				<h2>Login</h2>
				<div style="width: 60%; margin: 0px auto;">
					<?php include(ROOT_PATH . '/includes/errors.php') ?>
				</div>
				<input type="text" name="username" value="<?php echo $username; ?>" placeholder="Username">
				<input type="password" name="password"  placeholder="Password"> 
				<button class="btn" type="submit" name="login_btn">Sign in</button>
			</form>
		</div>
	</div>
<?php } ?>

<?php require_once( ROOT_PATH . '/includes/registration_login.php') ?>