<?php

class DB{

    private $link;

    public function __construct($host,$user,$password,$dbname,$port)

    {

        $link = mysqli_connect($host,$user,$password,$dbname,$port);

        if(!$link){

           echo "数据库连接失败";

           exit();

        }

        $this->link = $link;

    }

    //增加

    public function insert($table,$data){

        $sql = "";

        $sql.= "insert into `$table` ";

        $sql.= "(".implode(",",array_keys($data)).")";

        $sql.= " VALUES";

        $sql.= "('".implode("','",$data)."')";

        $res = mysqli_query($this->link,$sql);

        if($res && mysqli_affected_rows($this->link)>0){

            return mysqli_insert_id($this->link);

        }else{

            return false;

        }

    }

    //获取所有

    public function getAll($sql){

        $obj = mysqli_query($this->link,$sql);

        $data = mysqli_fetch_all($obj,1);

        return $data;

    }

    //删除

    public function delete($table,$where){

        $sql = "delete from `{$table}` where {$where}";

        $res = mysqli_query($this->link,$sql);

        if($res && mysqli_affected_rows($this->link)){

            return mysqli_affected_rows($this->link);

        }else{

            return false;

        }

    }

    //更新

    public function update($table,$data,$where){

        $sql = "update `$table` set";

        foreach ($data as $k=>$v){

            $sql .= "`{$k}` = '{$v}',";

        }

        $sql = rtrim($sql,',');

        $sql.= $where;

        $res = mysqli_query($this->link,$sql);

        if($res && mysqli_affected_rows($this->link)){

            return mysqli_affected_rows($this->link);

        }else{

            return false;

        }

    }

    //关闭数据库连接

    public function __destruct()

    {

        mysqli_close($this->link);

    }

}

$host = '127.0.0.1';

$user = 'root';

$password = 'root';

$dbname = '1903a';

$port = '3306';

$db = new DB($host,$user,$password,$dbname,$port);

$name = $_POST['name'];

$sex = $_POST['sex'];

$age = $_POST['age'];

if(empty($name)){

   echo "姓名不能为空";

   exit();

}

$name_reg = "/^[\x{4e00}-\x{9fa5}]{2,6}$/u";

if(!preg_match($name_reg,$name)){

    echo "用户名格式不正确";

}

//增加

$data = [

    'name'=> 'zhangsan',

    'age' => '18',

    'sex' => 1

];

//$res = $db->insert('user',$data);

//查询

//$sql = "select * from user";

//$data = $db->getAll($sql);

//删除

//$id = 9;

//$where = "id=$id";

//$res = $db->delete('user',$where);

//更新

//$data = [

//    'name'=> 'lisi',

//    'age' => 10,

//    'sex' => 2

//];

//$id = '10';

//$where = "where id=$id";

//$res = $db->update('user',$data,$where);

//var_dump($res);

?>