PDO方法实现增删改查

 1 <!DOCTYPE html>
 2 <html lang="en">
 3 <head>
 4     <meta charset="UTF-8">
 5     <title>登录，支持enter键</title>
 6 </head>
 7 <body>
 8 <h2>登录</h2>
 9 <form action="pdologincheck.php" method="post" name="addForm"  onsubmit="return CheckPost();">
10     <div>用户名:<input type="text"  name="username" /></div>
11     <div>密码:<input type="password" name="password" /></div>
12     <div><input type="submit" name="submit" value="登录"/></div>
13 </form>
14 <script language="javascript">
15     function CheckPost () {
16         if (addForm.username.value == "") {
17             alert('用户名不能为空')
18             addForm.username.focus();
19             //表单提交false不能少
20             return false;
21         }
22         if (addForm.password.value=="") {
23             alert('密码不能为空')
24             addForm.password.focus();
25             return false;
26         }
27 
28     }
29 </script>
30 </body>
31 </html>

php

 1 <?php
 2     header("Content-Type: text/html; charset=UTF-8");
 3     $username = $_POST['username'];
 4     $password = $_POST['password'];
 5     //连接数据库,分别表示：数据库地址，库名，用户名，密码
 6     try{
 7         $pdo=new PDO("mysql:host=localhost;dbname=test","root","root");
 8     }catch (PDOException $e){
 9         die("fail to connect mysql".$e->getMessage());
10     }
11     //查询
12     $sql="SELECT * FROM usermessage";
13     foreach($pdo->query($sql) as $val){
14         if($username==$val['username']&&$password==$val['password']){
15             echo "登录成功";
16             echo "<div>用户名：{$val['username']}密码：{$val['password']}</div>";
17             //立即跳转
18             //header('Location:index2.php');
19             //2秒后跳转
20             header('Refresh:2,Url=index2.php');
21             exit;
22         }
23     }
24     echo "登录失败";
25 ?>

注册增删改

 1 <?php
 2     header("Content-Type: text/html; charset=UTF-8");
 3     $username = $_POST['username'];
 4     $password = $_POST['password'];
 5     //连接数据库,分别表示：数据库地址，库名，用户名，密码
 6     try{
 7         $pdo=new PDO("mysql:host=localhost;dbname=test","root","root");
 8     }catch (PDOException $e){
 9         die("fail to connect mysql".$e->getMessage());
10     }
11     //增加数据
12     $sql="INSERT INTO usermessage VALUES('$username','$password')";
13 
14     //更新数据,修改username为$username的密码
15     //$sql="UPDATE usermessage set password='$password' WHERE username='$username'";
16 
17     //删除数据
18     //$sql="DELETE FROM usermessage WHERE username='$username'";
19 
20     if( $pdo->exec($sql) ){
21         echo "成功";
22     }else{
23         echo "失败";
24     }
25 ?>