POST请求返回的错误，在下菜鸟求助大牛帮忙

Question

//一下是mysql代码：
SET NAMES UTF8;
DROP DATABASE IF EXISTS lblist;
CREATE DATABASE lblist CHARSET=UTF8;
USE lblist;

CREATE TABLE lbuser(
uno INT PRIMARY KEY,
uname VARCHAR(32),
passwd VARCHAR(32)
);

INSERT INTO lbuser VALUES(1,'154494562','123456');

//下面是PHP
<?php
header('Content-Type: application/json');

$output = ['status'=>0, 'msg'=>''];
$uname = $_REQUEST['uname'];
$passwd = $_REQUEST['upwd'];

$conn = mysqli_connect('127.0.0.1','root','','lblist', 3306);
$sql="SELECT uno FROM lbuse WHERE uname='$uname' AND passwd='$passwd";
$result = mysqli_query($conn, $sql);
$row = mysqli_fetch_assoc($result);

if($row){
$output['status'] = intval($row['uno']); //把字符串转化为整数
$output['msg'] = $uname;
}else {
$output['status'] = -404;
$output['msg'] = '用户名或密码错误';
}

echo json_encode($output);
?>

Answer 1

$sql="SELECT uno FROM lbuse WHERE uname='$uname' AND passwd='$passwd";最后好像有问题