Return JSON Data from PHP and Ajax - php

Question

In my web application just I trying to returning JSON data from MySQL database using PHP and AJAX query. This is where I follow a tutorial on internet. In case in my application it shows and error like;
data = "↵↵↵↵Notice: Undefined index: lymph in
C:\xampp\htdocs\Hospital\hospitalwebsite\test_query\fetch_count.php
on line 29
Here is my AJAX Code :-
<script>
$(document).ready(function () {
$('select').material_select();
$('#search').click(function () {
var id = $('#test_list').val();
if (id != '') {
$.ajax({
url: 'test_query/fetch_count.php', // Url to which the request is send
method: 'POST', // Type of request to be send, called as method
data: { id: id },
//dataType:"JSON",
success: function (data) {
$('#success_mes').fadeIn().html(data);
$('#test_info').css('display', 'block');
$('#1').text(data.WBC);
$('#2').text(data.lymph);
$('#3').text(data.Mid);
}
});
} else {
alert('sdsd');
$('#test_info').css('display', 'none');
}
});
});
</script>
Below is the PHP Code :-
<?php
session_start();
require_once "../phpquery/dbconnection.php";
if (isset($_POST['id'])) {
//$id = $_POST['id'];
$stmt = $con->prepare("SELECT * FROM testing_report WHERE testing_report_id = ? AND test_id='7' ");
$stmt->bind_param("s", $_POST['id']);
$stmt->execute();
$result = $stmt->get_result();
if ($result->num_rows === 0);
while ($row = $result->fetch_assoc()) {
$medRecords = json_decode($row['testing_results'], true);
if (is_array($medRecords) || is_object($medRecords)) {
foreach ($medRecords as $key => $object) {
$data["WBC"] = $object['WBC'];
$data["lymph"] = $object['lymph'];
$data["Mid"] = $object['Mid'];
}
}
}
echo json_encode($data);
}
?>
SQL schema
Really I am appreciating if someone can help me. Thank you

Answer 1

The issue is that your data structure is split over several array elements, something like...
[
{
"WBC": "1"
},
{
"lymph": "5"
}
]
so each loop round the array only has 1 piece of information. This code combines all of that data into 1 set of information using array_merge() and then extracts the data from the result.
I've also added ?? 0 to default the values to 0 if not present, there may be a better default value.
$data = [];
$medRecords = json_decode($row['testing_results'], true);
if (is_array($medRecords) || is_object($medRecords)) {
$medRecords = array_merge(...$medRecords);
$data["WBC"] = $medRecords['WBC'] ?? 0;
$data["lymph"] = $medRecords['lymph'] ?? 0;
$data["Mid"] = $medRecords['Mid'] ?? 0;
}

Answer 2

JQuery work file if the result be json:
$(document).ready(function(){
$('#search').click( function () {
$.ajax({
url: "https://reqres.in/api/users?page=2",
method: "GET",
success:function(data)
{
console.log("page:", data.page);
console.log(data);
}
});
});
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<button id="search">Search</button>
i think you have to add correct header to your result:
<?php
header('Content-Type: application/json');
add this code into first line of your php page. then jQuery know result is json.