Tạo Trang Login Đơn Giản Bằng PHP - MySSQL

1. Tạo CSDL trong MySQL:

mysql>create database project;
mysql>use project;
mysql>create table user(
id INT(10) UNSIGNED NOT NULL AUTO_INCREMENT,
username VARCHAR(50) NOT NULL,
password CHAR(50) NOT NULL,
level CHAR(1) NOT NULL,
PRIMARY KEY(id));
mysql>insert into user(id,username,password,level) values (1,'admin','123456',2);

2. Tạo file "login.html" có nội dung như sau:

<html>
<head>
</head>
<body>
<form action='login.php' method='GET'>
Username: <input type='text' name='username' size='25' /><br />
Password: <input type='password' name='password' size='25' /><br />
<input type='submit' name='ok' value='Dang Nhap' />
</form>
</body>
</html>

3.Tạo file "login.php" có nội dung như sau:

<html>
<head>
</head>
<body>
<?phpif(isset($_GET['ok'])){$u=$p="";
if($_GET['username'] == NULL) {
echo "Ban Chua Nhap UserName <br/>";
} else {
$u=$_GET['username'];
}
if($_GET['password'] == NULL) {
echo "Ban Chua Nhap Password <br />";
} else {
$p=$_GET['password'];
}
if($u && $p) {
$conn=mysql_connect("127.0.0.1","root","") or die("can't connect this database"); mysql_select_db("project",$conn);
$sql="select * from user where username='".$u."' and password='".$p."'"; $query=mysql_query($sql);
if(mysql_num_rows($query) == 0) { // Nhap sai quay lai trang login header("location:login.html");
} else {
$row=mysql_fetch_array($query);
session_start(); $_SESSION['userid'] = $row["id"];
$_SESSION['level'] = $row["level"];
header("location:successful.html");
}
}
}
?>
</body>
</html>