我尝试使用ajax从数据库检索数据，但没有成功。这些是我正在使用的代码。我没有看到任何具体的错误控制台。
html格式：

<button type="button" name="result_submit" id="result_submit" >Submit</button>
<div class="result" id="result" name="result"> </div>

jquery查询：

$(document).ready(function(e) {
    $('#result_submit').click(function() {

        $.ajax({
            url  :"Income.php",
            type :'POST',
            success: function(data){
                $("#result").html(data);
            }
        });
    }); 
});

income.php内容：

<?php

include_once 'dbConnection.php';

$stmt = mysqli_stmt_init($conn);

$income = "select SUM(amount) as incomeNumber FROM wp_formdata WHERE entry_type='Income'";

    if(!mysqli_stmt_prepare($stmt,$income)) 

        {
            $message =  '<h1 style="color:red;padding-top:5%;">SQL Error !!</h1>';
        } 
        else 
        {
            mysqli_stmt_execute($stmt);
            $result= mysqli_stmt_get_result($stmt);
            $income_sum=mysqli_fetch_assoc($result); 
            $TotIncome= "Total Income is ".$income_sum['incomeNumber'];
        }
?>

dbconnection.php包含连接详细信息：

<?php

$dbServername = "localhost";    
$dbUsername = "root";
$dbPassword = "";
$dbName = "wordpress";

$conn= mysqli_connect($dbServername, $dbUsername, $dbPassword, $dbName);

?>

有人能指导我如何解决这个问题吗