How do I run a php script on Angular on input change? - php

Question

It seems that I am having trouble running an SQL query on the server via PHP on Input change. Could someone please take a look on my code and assist me?
The service that is responsible for handling the http request to the server:
import { Injectable } from '#angular/core';
import { HttpClient } from "#angular/common/http";
#Injectable({
providedIn: 'root'
})
export class CrudService {
public url = 'http://localhost/web_api/';
constructor(private http: HttpClient) { }
registerNormal(data)
{
return this.http.post(this.url + 'registerNormal.php', data);
}
accountExists(data)
{
return this.http.get(this.url + 'existingAccounts.php', data);
}
}
The function responsible for passing the data
CheckAccountAvailability(values)
{
const registerNormalFormData = new FormData();
registerNormalFormData.append('username', values.username);
if (this.registerNormal.get('username').valid)
this.crudService.accountExists(registerNormalFormData).subscribe(result => {console.log(result)});
}
The PHP file works fine since I have tested it with postman and also the registerNormal() function works perfectly fine.
I don't seem to pinpoint the issue exactly.
Many thanks!
EDIT:
Below is the html code for the component that calls the function. The function gets called but the result returned by angular is NULL however the PHP API returns the result fine with postman
<input matInput placeholder="User Name" formControlName="username" required (input)="CheckAccountAvailability(registerNormal.value)">
EDIT 2:
Below is the php code for existingAccounts.php
<?php
if ($_GET)
{
// include database connection
include 'config/database.php';
try
{
// check if account exists in database
$q_normalAccountExists = "SELECT * FROM normal_accounts WHERE username=:username";
// $q_bandAccountExists = "SELECT * FROM band_accounts WHERE username=:username";
// prepare queries to check if accounts exist in database
$checkNormalAccount = $con->prepare($q_normalAccountExists);
// $checkBandAccount = $con->prepare($q_bandAccountExists);
// GET username
$username = $_GET['username'];
// bind parameters to check if username exists in database
$checkNormalAccount->bindParam(':username', $username);
// $checkBandAccount->bindParam(':username', $username);
// execute username exists in database query
$checkNormalAccount->execute();
// $checkBandAccount->execute();
if ($checkNormalAccount->rowCount() == 0/* && $checkBandAccount->rowCount() == 0*/)
{
echo json_encode(array('result'=>false));
}
else
{
echo json_encode(array('result'=>true));
}
}
// show error
catch(PDOException $exception)
{
die('ERROR: ' . $exception->getMessage());
}
}
?>
EDIT 3:
It seems that changing the GET request to a POST request sorted the issue. However, could anyone tell me why GET requests won't work?