Display database fields with some conditions - php

Question

I want to display the invoice bill for each customer when admin clicks on view bill button for that customer. Also I want to display all the newspaper details in a single invoice when customer name is same.I have included the relevant code and database snapshots.
c_details.php
<?php
session_start();
include_once("connect.php");
$query="SELECT * FROM sub_details";
$result=mysqli_query($conn,$query);
?>
<table align="center">
<h3 style="color: black; font-weight: bold; text-align: center;">
Subscription details</h3><br>
<tr>
<th style="text-align: center;">Id</th>
<th style="text-align: center;">Name</th>
<th style="text-align: center; width: 900px">Newspaper</th>
<th style="text-align: center;">Duration</th>
<th style="text-align: center;">Price</th>
<th style="text-align: center; width: 800px">Subscription date</th>
<th style="text-align: center;">Remaining Days</th>
<th style="text-align: center;">Bill</th>
</tr>
<?php while($rows=mysqli_fetch_assoc($result)) {
?>
<tr>
<td><?php echo $rows['id']; ?></td>
<td><?php echo $rows['name']; ?></td>
<td><?php echo $rows['newspaper']; ?></td>
<td><?php echo $rows['duration']; ?></td>
<td><?php echo $rows['price']; ?></td>
<td><?php echo $rows['sdate']; ?></td>
<?php echo var_dump($result->fetch_all(MYSQLI_ASSOC));
$date1=date_create();
$date2=date_create($rows['edate']);
$interval=date_diff($date2,$date1)->format("%a days");
?>
<td><?php echo $interval; ?></td>
<td>
<form action="invoice.php" method="GET">
<?php $invoiceId = $rows['name']; ?>
<button type="submit" onclick= "window.open('invoice.php?name= '<?php echo
$rows['name']; ?>)" class="btn btn-primary btn-lg" value="submit" >
View bill</button></td>
</form>
</tr>
<?php } ?>
</table>
invoice.php
<?php
include_once("connect.php");
$invoiceId = isset($_GET['name']) ? $_GET['name'] : null;
if($invoiceId) {
$query = "SELECT * FROM sub_details WHERE name = ? limit 1";
$result = mysqli_query($conn,$query);
?>
<?php while($rows=mysqli_fetch_assoc($result)) {
?>
<form style="text-align: left;margin-left: 30px" class="register-form" id="register-form">
<div class="form-group"> Bill no: <input type="text" name="id" value="<?php echo $rows['id']; ?>"></div><br>
<div class="form-group">Name: <input type="text" name="name" value="<?php echo $rows['name']; ?>"></div><br>
<div class="form-group">Address: <input type="text" name="address" value="<?php echo $rows['address']; ?>"></div><br><br>
</form>
</th>
</tr>
<td>
<table cellpadding="5px" cellspacing="6px" style="width: 75%; border-radius:20px;">
<tr>
<th>Newspaper</th>
<th >Duration</th>
<th >Price</th>
</tr>
<tr>
<td ><?php echo $rows['newspaper']; ?></td>
<td><?php echo $rows['duration']; ?></td>
<td><?php echo $rows['price']; ?></td>
</tr>
<tr>
<td>DELIVERY CHARGES</td>
<td colspan="3" style="padding-right:60px;text-align: right;">50</td>
</tr>
<tr>
<th>Total</th>
<?php
$t_price=$rows['price']+ 50; ?>
<th colspan="3" style="text-align: right;padding-right: 55px"><?php echo $t_price; ?></th>
</tr>
<tr>
<th colspan="4" >
<br><br><br><br><br><br><br>
</th>
</tr>
</table>
</td>
<tr>
<th colspan="4" style="border-top-color: #ffff4d">
<p style="text-align: left;">Note: Clients are requested to pay the bill before 5th of every month.</p>
</th>
</tr>
<?php } ?>
</table>
Database screenshots

Answer 1

First, you should pass the invoice ID for each record in c_details.php so that you can identify them later:
<button type="submit" onclick= "window.open('invoice.php?id='<?php echo $rows['id']; ?>)" class="btn btn-primary btn-lg" value="submit" >View bill</button>
It will produce URLs like invoice.php?id=<id>, where <id> is the ID for each record in the database. So, for example, a record with the ID 102 will be invoice.php?id=102.
On invoice.php, you can retrieve the ID with $_GET['id']. You should adjust your query to fetch the data for the given invoice:
$invoiceId = isset($_GET['id']) ? $_GET['id'] : null;
if($invoiceId) {
$query = $conn->prepare("SELECT * FROM sub_details, signup_c WHERE id = ? limit 1";
$query->bind_param('s', $invoiceId);
$query->execute();
$result = $query->get_result();
}
If you're using PHP 7.0 or later, you can simplify your code using the null coalescing operator:
$invoiceId = $_GET['id'] ?? null;
I strongly recommend you to learn about how to prevent SQL injections in PHP.