MySQL-DB-封装-简易版

<?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);
?>