$mysqli=@new mysqli(‘localhost‘,‘root‘,‘‘,‘sqldb‘);
    if(mysqli_connect_errno()){
        echo "链接错误".$mysqli->error.":".$mysqli->errno;
    }
    //关闭自动提交
    $mysqli->autocommit(0);
    $error=true;
    $zhuan=50;
    //张三
    $sql="update user set total=total-{$zhuan} where name=‘zhangsan‘";
    $result=$mysqli->query($sql);
    if(!$result){
        $error=false;
        echo "张三转账失败";
        
    }else{
        if($mysqli->affected_rows==0){
            $error=false;
            echo "张三的钱没有变化";
            
        }else{
            $error=true;
            echo "张三转账成功";
            
        }
    }
    //李四
    $sql="update user set total=total+{$zhuan} where name=‘lisi‘";
    $result=$mysqli->query($sql);
    if(!$result){
        $error=false;
        echo "李四转入失败";
        
    }else{
        if($mysqli->affected_rows==0){
            $error=false;
            echo "李四的钱没有变化";
            
        }else{
            $error=true;
            echo "李四转入成功";
            
        }
    }
    if($error){
        echo "转账成功";
        $mysqli->commit();
        
    }else{
        echo "转账失败";
        $mysqli->rollback();
    }

    $mysqli->autocommit(1);