$mysqli=@new mysqli(‘localhost‘,‘root‘,‘‘,‘sqldb‘);    if(mysqli_connect_errno()){        echo "链接错误".$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);