php select query with where parameter error - php

Question

I have written a php script to retrieve data from mysql for a particular username. The username is passed in select query and i am checking the php script using postman. Following is my php code
<?php
//getting the database connection
require_once 'MyDbConnect.php';
//an array to display response
$response = array();
//if it is an api call
//that means a get parameter named api call is set in the URL
//and with this parameter we are concluding that it is an api call
if(isset($_GET['apicall'])){
switch($_GET['apicall']){
case 'getSpecificData':
case 'getSpecificData':
if(isTheseParametersAvailable(array('your_username'))){
//getting values
$your_username = $_POST['your_username'];
$heroes = array();
$sql = "SELECT your_username,your_mobile,referral_name,referral_contact,referral_email,
loan_type,loan_amount FROM mytable WHERE your_username = ? ";
$sql->bind_param("s",$your_username);
$stmt->execute();
$stmt->bind_result($your_username, $your_mobile,$referral_name,$referral_contact,
$referral_email,$loan_type,$loan_amount);
//looping through all the records
while($stmt->fetch()){
$temp = [
'your_username'=>$your_username,
'your_mobile'=>$your_mobile,
'referral_name'=>$referral_name,
'referral_contact'=>$referral_contact,
'referral_email'=>$referral_email,
'loan_type'=>$loan_type,
'loan_amount'=>$loan_amount
];
//pushing the array inside the hero array
array_push($heroes, $temp);
}
echo json_encode($heroes);
}
break;
default:
$response['error'] = true;
$response['message'] = 'Invalid Operation Called';
}
}
else{
//if it is not api call
//pushing appropriate values to response array
$response['error'] = true;
$response['message'] = 'Invalid API Call';
}
function isTheseParametersAvailable($params){
//traversing through all the parameters
foreach($params as $param){
//if the paramter is not available
if(!isset($_POST[$param])){
//return false
return false;
}
}
//return true if every param is available
return true;
}
?>
The problem is in the select query. When i write the select query as i mentioned above in my php code i get nothing. but if i write the select query as follows i get proper data
$sql = "SELECT your_username,your_mobile,referral_name,referral_contact,referral_email,
loan_type,loan_amount FROM mytable WHERE your_username = 'Rohan' ";
Can somebody please explain me the cause of error? Any help would be greatly appreciated.

Answer 1

You're missing the binding of the variable:
// $stmt->bind_param("ss",$your_username);
Is already in your code. Change it to:
$stmt->bind_param("s",$your_username);
The "s" indicates the variable is a string, the binding "replaces" the "?" in the query.
EDIT:
Than use this snippet instead ;)
$your_username = $_POST['your_username'];
//creating the query
$stmt = $conn->prepare("SELECT id,your_username,your_mobile,referral_name,referral_contact,referral_email,
loan_type,loan_amount FROM mytable WHERE your_username = ? ");
$stmt->bind_param("s",$your_username);