警告：mysqli_num_rows（）期望参数1为mysqli_result，给定布尔值（HELP！）

Question

嗨，大家好，在创建一个PHP脚本后，我一直有这个错误：

  

警告：mysqli_num_rows（）期望参数1为mysqli_result，   第14行的C：\ wamp64 \ www \ login.php中给出的布尔值

这是我的代码：

<?php
require "init.php";

if(isset($_POST["user_name"]))  {

$user_name = $_POST["user_name"];
$password = $_POST["password"];
}
$sql = "select name email from user_info where user_name like        '".$user_name."' and password like '".$password."';";

$result = mysqli_query($con, $sql);
$response = array();

if(mysqli_num_rows($result) > 0)
{
$row = mysqli_fetch_row($result);
$name = $row[0];
$email = $row[1];
$code = "login_success";
array_push($response,array("code"=>$code,"name"=>$name,"email"=>$email));
echo json_encode($response);
}
else
{
$code = "login_failed";
$message = "User not found... Please try again...";
array_push($response,array("code"=>$code, "message"=>$message));
}
mysqli_close($con);


?>