Using GET to retrieve Data from my Webpage - post

Question

I'm trying to use an ESP8266 NodeMCU to retrieve data from a database on my web page to control a LED. I'm struggling with the code on both sides for the ESP8266 to ask for the data and the web page to return it. I have the web page and database built. Here is the relevant bit of the server side PHP file, which isn't working....
if(!empty($_GET['mode']) && !empty($_GET['brightness']))
{
$mode = $_GET['mode'];
$brightness = $_GET['brightness'];
$sql = "SELECT * FROM config ORDER BY id DESC LIMIT 1 (mode, brightness)
$result = $conn->query($sql);
SELECT fields FROM table ORDER BY id DESC LIMIT 1;
VALUES ('".$mode."', '".$brightness."')";
if ($conn->query($sql) === TRUE) {
echo "1" . $row["id"]."<br>";
} else {
echo "Error: " . $sql . "<br>" . $conn->error;
}
}
$conn->close();
<code>
and on the ESP8266 side....
getData = "?mode=" "&brightness=";
Link = "http://***.com/Feed.php" + getData;
http.begin(Link); //Specify request destination
int httpCode = http.GET();
String payload = http.getString();
Mode = payload.substring(0,3);
String Brightness = payload.substring (4,6);
Thanks in advance!

Answer 1

I changed my approach and got it working. Instead of trying to return data from the web page to the ESP8266 I displayed the data on a very simple page....
<?php
$con=mysqli_connect("localhost","*****","*****","*****");
if (mysqli_connect_errno()) { echo "Failed to connect to config: " . mysqli_connect_error(); }
$result = mysqli_query($con,"SELECT * FROM config ORDER BY id DESC LIMIT 1");
while ($row = $result->fetch_assoc()) {
$mode = $row[mode]; $brightness = $row[brightness]; $speed = $row[speed];
print $mode;
print $brightness;
print $speed;
}
?>
and then had the ESP download the entire page and parsed out the data using substring like so...
HTTPClient http; //Declare object of class HTTPClient
Link = "http://*****.com/*****.php";
http.begin(Link); //Specify request destination
int httpCode = http.GET(); //Send the request
String payload = http.getString(); //Get the response payload
Mode = payload.substring(156,158).toInt();
Speed = payload.substring(158,160).toInt();
Brightness = payload.substring(160,162).toInt();