Examples of php mysqli extension library operating mysql

This article shares several examples of PHP using the mysqli extension to operate the mysql database. It is quite good. Friends in need can refer to it. It will definitely be helpful.

1. The mysqli extension library operates the dql of mysql

<?php
    header("Content-type: text/html;charset=utf-8");
    //mysqli操作mysql数据库(面向对象方式)

    //1、创建MySQLi对象
    $mysqli =new MySQLi("localhost","root","root","test");
    if($mysqli->connect_error){
        die("连接失败".$mysqli->connect_error);
    }

    //2、操作数据库（发送sql）
    $sql="select *from user1";

    //3、处理结果
    $res =$mysqli->query($sql);
    //var_dump($res);
    //fetch_assoc \fetch_array \fetch_object
    while($row=$res->fetch_row()){

        var_dump($row);

/*        foreach($row as $val){
            echo '--'.$val;
        }
        echo '<br/>';*/
    }
    //4、关闭资源
    $res->free();
    $mysqli->close();
?>

Process-oriented example:

<?php
    header("Content-type: text/html;charset=utf-8");
    
    $mysqli=mysqli_connect("localhost","root","root","test");
    if(!$mysqli){
        die("连接失败".mysqli_connect_error());
    }

    $sql="select *from user1";

    $res=mysqli_query($mysqli,$sql);
    //var_dump($res);

    while($row=mysqli_fetch_row($res)){
        
        foreach ($row as $val){
            
            echo '-'.$val;
        }
        echo '<br/>';
    }

    //释放内存
    mysqli_free_result($res);
    mysqli_close($mysqli);
?>

2. Mysqli extension library’s dml operation on mysql

<?php
    
    //使用mysqli 扩展库对mysql的crud 操作
    header("Content-type: text/html;charset=utf-8");
    $mysqli = new MySQLi("localhost","root","root","test");

    if($mysqli->connect_error){
        die("连接失败".$mysql->connect_error);
    }

    //增加一条记录
    //$sql="insert into user1 (name,password,email,age) values ('lucy',md5('lucy'),'lucy@163.com',17)";
    //删除一条记录
    //$sql="delete from user1 where id =80";
    //更新一条记录
    $sql="update user1 set age=20 where id=7";

    $res=$mysqli->query($sql);
    if(!$res){
        echo "操作失败".$mysqli->error;
    }else{
        if($mysqli->affected_rows>0){
            echo "成功";
        }else{
            echo "没有行受影响";    
        }
    }

    //关闭资源
    $mysqli->close();
?>

3. Encapsulate

<?
class SqlHelper{        
        private $mysqli;
        //这里先写死，以后写死的东西用一个文件来配置
        private static $host="localhost";
        private static $user="root";
        private static $pwd="root";
        private static $db="test";

        public function __construct(){
            
            $this->mysqli=new MySQLi(self::$host,self::$user,self::$pwd,self::$db);
            if($this->mysqli->connect_error){
                die("连接失败".$this->mysqli->connect_error);
            }
            //设置字符集
            $this->mysqli->query("set names utf8");
        }

        //dql operate
        function execute_dql($sql){

            $res =$this->mysqli->query($sql) or die($this->mysqli->error);
            return $res;        
        }

        //dml operate
        function execute_dml($sql){

            $res =$this->mysqli->query($sql) or die($this->mysqli->error);
            
            if(!$res){
                return 0;//失败
            }else{
                if($this->mysqli->affected_rows>0){
                    return 1;//成功
                }else{
                    return 2;//没有行到影响
                }
            }
        }
    }
?>