Untitled

<?php
	class transport
	{
		private $model;
		private $speed;
		public function setSpeed($arg)
		{
			$this->speed = $arg;
		}
		public function getSpeed()
		{
			return $this->speed;
		}
	}
	class automobile extends transport
	{
		private $fuelType;
		function __construct($arg)
		{
			$this->fuelType = $arg;
		}
		public function getFuelType()
		{
			return $this->fuelType;
		}
	}
	class airplane extends transport
	{
		private $wingspan;
		public function setWingSpan($arg)
		{
			$this->wingspan = $arg;
		}
		public function getWingSpan()
		{
			return $this->wingspan;
		}
	}
?>

<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
	</head>
	<body>
		<?php
			$auto = new automobile("diesel");
			$auto->setSpeed(180);
			$plane = new airplane();
			$plane->setWingSpan(30);
			$plane->setSpeed(100);
			echo $auto->getSpeed() . PHP_EOL;
			echo $plane->getSpeed();
		?>

		<center><?php
if(!$mcon = mysqli_connect('localhost', 'root', '')) die("Не може да се свърже с бази данни");
		 if(!mysqli_select_db($mcon,'my_library')) die("Не може да се свърже с таблицата в БД");
		if(isset($_POST['addnew']) && !empty($_POST['addnew'])){


		 $bookisbn = mysqli_escape_string($mcon,$_POST['isbn']);
		 $bookName = mysqli_escape_string($mcon,$_POST['book_name']);
		 $bookAuthor = mysqli_escape_string($mcon,$_POST['author_name']);
		 $bookPrice = mysqli_escape_string($mcon,$_POST['price']);
		 $bookCount = mysqli_escape_string($mcon,$_POST['books_count']);
		 if(!mysqli_query($mcon,"INSERT INTO library (isbn,book_title,author,price,books_count)
		 	VALUES ('$bookisbn','$bookName','$bookAuthor','$bookPrice','$bookCount')"))
		  die("ГРЕШКА ПРИ ДОБАВЯНЕ НА НОВА КНИГА");
		 echo "<h2>You have added a new book!</h2><br><br>";

			}

			 if(isset($_POST['borrowbook']) && !empty($_POST['borrowbook'])){
		 		$bookName = mysqli_escape_string($mcon,$_POST['book_name']);
		 		if(!$data = mysqli_query($mcon,"SELECT * FROM library WHERE book_title = '$bookName'"))
		  die("ГРЕШКА ПРИ ЗАЕМАНЕ НА КНИГА");
				$result = mysqli_fetch_array($data);
				$isbn = $result['isbn'];
				if($result['books_count']>1){
					if(!mysqli_query($mcon,"UPDATE library SET books_count = books_count - 1 WHERE isbn = '$isbn'"))
						die("ГРЕШКА ПРИ ЗАЕМАНЕ НА КНИГА");
		 echo "<h2>You have borrowed a book with ISBN:$isbn!</h2><br><br>";
		}else echo "<h2>There is only one book, you cannot borrow now!</h2><br><br>";

			}
			if(isset($_POST['returnbook']) && !empty($_POST['returnbook'])){
		 		$bookName = mysqli_escape_string($mcon,$_POST['book_name']);
		 		if(!$data = mysqli_query($mcon,"SELECT * FROM library WHERE book_title = '$bookName'"))
		  die("ГРЕШКА ПРИ ВРЪЩАНЕ НА КНИГА");
				$result = mysqli_fetch_array($data);
				$isbn = $result['isbn'];
					if(!mysqli_query($mcon,"UPDATE library SET books_count = books_count + 1 WHERE isbn = '$isbn'"))
					 die("ГРЕШКА ПРИ ЗАЕМАНЕ НА КНИГА");
		 echo "<h2>You have returned a book with ISBN:$isbn!</h2><br><br>";
		}
		?>
			<h2>Add a new book:</h2>
			<form method="POST">
				ISBN of book:<br>
				<input type="text" name="isbn"><br>
				Book name:<br>
				<input type="text" name="book_name"><br>
				Author name:<br>
				<input type="text" name="author_name"><br>
				Price:<br>
				<input type="text" name="price"><br>
				Books count:<br>
				<input type="number" name="books_count"><br><br><br>

				<input type="submit" name="addnew"><br>
			</form>
			<br><br>
			<h2>Borrow/return a book:</h2>
			<form method="POST">
				Book name:<br>
				<input type="text" name="book_name"><br>
				<input type="submit" name="borrowbook" value="borrow"><br>
				<input type="submit" name="returnbook" value="return"><br>
			</form>
		</center>
	</body>
</html>