oop简易封装增删改查

//注意要先引入含有封装类的文件文件：如下：

<?php
class Db{
    public $host='127.0.0.1';
    public $user='root';
    public $pass='root';
    public $name='day4';
    public $link;
    function __construct()
    {
     $this->link= mysqli_connect($this->host,$this->user,$this->pass,$this->name);
    }
function add($sql){
      return  mysqli_query($this->link,$sql);
}
function select($sql){
     $resu= mysqli_query($this->link,$sql);
     return  mysqli_fetch_all($resu,1);
}
function del($sql){
      return mysqli_query($this->link,$sql);
}
function  selects($sql){
    $result=mysqli_query($this->link,$sql);
       return mysqli_fetch_assoc($result);
}
function update($sql){
     return   mysqli_query($this->link,$sql);
}
function __destruct()
{
    // TODO: Implement __destruct() method.
    mysqli_close($this->link);
}
}

1.......................

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<!--利用前端页面进行用户的登录-->
<form action="reg.php" method="post">
  <p> 账号： <input type="text" name="name" id=""></p>
    <p>   密码：<input type="password" name="pass"></p>
    <p> <input type="submit" value="立即登录"></p>
</form>
</body>
</html>


2.................................

<?php
$name=$_POST['name'];
$pass=$_POST['pass'];
//验证非空
if (empty($name)){
    echo '登录账号不可以为空';
    header('refresh:3,url=deng.php');
    die;
}
if (empty($pass)){
    echo '登录密码不可以为空';
    header('refresh:3,url=deng.php');
    die;
}
include 'db.php';
//进行添加的SQL语句
$obj=new Db();
$sql="insert into lu value (null,'$name','$pass')";
$result=$obj->add($sql);
if ($result){
    echo '添加成功';
    header('refresh:3,url=zhan.php');
    die;
}else{
    echo '添加失败';
    header('refresh:3,url=deng.html');
    die;
}
3............................................

<?php
//添加成功就回进入数据库，然后进行展示
echo "这是展示页面";
include 'db.php';
$sql="select * from lu";
$obj=new Db();
 $result=$obj->select($sql);
?>
<table border="1">
    <tr>
        <td>id号</td>
        <td>账号</td>
        <td>密码</td>
        <td>操作</td>
    </tr>
    <?
    foreach ($result as $k=>$v){
    ?>
    <tr>
        <td><?echo $v['id']?></td>
        <td><? echo  $v['name']?></td>
        <td><? echo $v['pass']?></td>
        <td><a href="shan.php?id=<? echo $v['id']?>">删除</a>
            <a href="xiu.php?id=<? echo $v['id'] ?>">修改</a>
        </td>
    </tr>
    <?
    }
    ?>

</table>


4................................

<?php
///利用id进行传值，利用id进行删除
$id=$_GET['id'];
include 'db.php';
$sql="delete from lu where id='$id'";
//访问类，进行删除
$obj=new Db();
$result=$obj->del($sql);
if ($result){
    echo '删除成功';
    header('refresh:3,url=zhan.php');
    die;
}
echo '删除失败';
header('refresh:3,url=zhan.php');
die;
5.................................

<?php
//点击修改后,展示默认值，进行修改。
$id=$_GET['id'];
include 'db.php';
//sql语句
$sql="select * from lu where id='$id'";
$obj=new Db();
$data=$obj->selects($sql);

?>
<form action="gai.php" method="post">
<table border="1">
    <p> 账号： <input type="text" name="name" value="<?echo $data['name']?>"></p>
    <p>   密码：<input type="password" name="pass" value="<? echo $data['pass'] ?>"></p>
    <p><input type="hidden" name="id" value="<? echo $data['id']?>"></p>
    <p> <input type="submit" value="立即修改"></p>

</table>
</form>

6...............................................................

<?php
//print_r($_POST);
//利用隐藏的input传进来的id进行修改某一条数据
$name=$_POST['name'];
$pass=$_POST['pass'];
$id=$_POST['id'];
include 'db.php';
$sql="update lu set name='$name',pass='$pass'where id='$id'";
$obj=new Db();
$data=$obj->update($sql);
if ($data){
    echo '修改成功';
    header('refresh:3,url=zhan.php');
    die;
}else{
    echo '修改失败';
    header('refresh:3,url=zhan.php');
    die;
}