PHP - Is Converting Product Price To Cents The Best Way To Store Value In The Database?

I am getting ready to code my e-commerce module, and could use some helping figuring out how to submit the product price.

On the product details page, if I have a button called "Add to Cart", would I want to use a hidden HTML field to submit the "product_price"?

<?php
require('../fpdf/fpdf.php');
include_once'../db/connect_db.php';

$id = $_GET['id'];
$select = $pdo->prepare("SELECT * FROM tbl_invoice WHERE invoice_id=$id");
$select->execute();
$row = $select->fetch(PDO::FETCH_OBJ);

$pdf = new FPDF('P','mm', array(80,200));

$pdf->AddPage();

$pdf->SetFont('Arial','B',16);
$pdf->Cell(60,10,'Haske Eye Specialist',0,1,'C');

$pdf->Line(10,18,72,18);
$pdf->Line(10,19,72,19);

$pdf->SetFont('Arial','',8);
$pdf->Cell(60,3,'No 16 Musa Shehu Close',0,1,'C');

$pdf->SetFont('Arial','',8);
$pdf->Cell(63,3,'Behind Nunu International School, Kawo Kaduna',0,1,'C');

$pdf->SetFont('Arial','',8);
$pdf->Cell(63,4,'No. Telp: +234 09015445656',0,1,'C');

$pdf->Line(10,30,72,30);
$pdf->Line(10,31,72,31);

$pdf->SetY(31);
$pdf->SetFont('Arial','B',10);
$pdf->Cell(60,6 ,'Purchase Orders',0,1,'C');

$pdf->SetFont('Courier','B',8);
$pdf->Cell(20,4 ,'Rept No.     :',0,0,'C');

$pdf->SetFont('Courier','BI',8);
$pdf->Cell(10,4 ,$row->invoice_id,0,1,'C');

$pdf->SetFont('Courier','B',8);
$pdf->Cell(20,4 ,'User name :',0,0,'C');

$pdf->SetFont('Courier','BI',8);
$pdf->Cell(10,4 ,$row->cashier_name,0,1,'C');

$pdf->SetFont('Courier','B',8);
$pdf->Cell(20,4 ,'Date & Time:',0,0,'C');

$pdf->SetFont('Courier','BI',8);
$pdf->Cell(21,4 ,$row->order_date,0,0,'C');

$pdf->SetFont('Courier','BI',8);
$pdf->Cell(10,4 ,$row->time_order,0,1,'C');
//////////////////////////////////////////////
$pdf->SetY(55);

$pdf->SetX(6);
$pdf->SetFont('Arial','B',8);
$pdf->Cell(27,8 ,'Product',1,0,'C');
$pdf->SetFont('Arial','B',8);
$pdf->Cell(7,8 ,'Qty',1,0,'C');
$pdf->SetFont('Arial','B',8);
$pdf->Cell(18,8 ,'Price',1,0,'C');
$pdf->SetFont('Arial','B',8);
$pdf->Cell(18,8 ,'Total',1,1,'C');

$select = $pdo->prepare("SELECT * FROM tbl_invoice_detail WHERE invoice_id=$id");
$select->execute();
while($item = $select->fetch(PDO::FETCH_OBJ)){
    $pdf->SetX(6);
    $pdf->SetFont('Arial','B',8);
    $pdf->Cell(27,5,$item->product_name,1,0,'L');
    $pdf->Cell(7,5,$item->qty,1,0,'C');
    $pdf->SetFont('Arial','B',7);
    $pdf->Cell(18,5,'Naira '.number_format($item->price),1,0,'R');
    $pdf->Cell(18,5,'Naira '.number_format($item->total),1,1,'R');
}

//////////////////////////////////////////////
$pdf->SetX(43);
$pdf->SetFont('Arial','Bi',8);
$pdf->Cell(25,8 ,'Total  :',0,0,'C');

$pdf->SetFont('Arial','BI',7);
$pdf->Cell(1,8 ,'Naira ' . number_format($row->total),0,1,'C');

$pdf->SetX(43);
$pdf->SetFont('Arial','BI',7);
$pdf->Cell(25,4 ,'Paid   :',0,0,'C');

$pdf->SetFont('Arial','BI',7);
$pdf->Cell(1,4 ,'Naira '. number_format($row->paid),0,1,'C');

$pdf->SetX(43);
$pdf->SetFont('Arial','BI',8);
$pdf->Cell(25,8 ,'Due    :',0,0,'C');

$pdf->SetFont('Arial','BI',7);
$pdf->Cell(1,8 ,'Naira '. number_format($row->due),0,1,'C');

//////////////////////////////////////////////
$pdf->SetY(80);
$pdf->SetX(7);
$pdf->SetFont('Arial','BU',5);
$pdf->Cell(75,4 ,'Returns Drugs Are Not Accepted',0,1,'L');

$pdf->SetFont('Arial','BU',5);
$pdf->Cell(45,4 ,'Collect Your Receipt ans Call:-09015445656 for Enquiries',0,0,'C');

$pdf->Output();

Hi all,

How can i auto populate the price of an item based on a chosen product and then auto calculate the price and quantity before hitting the ADD button.
I think it should be a javascript/ajax/jquery stuff but dont know how to go about it.

The Unit price should be auto populated based on valu from the database. The amount is the Unit Price times the Quantity of the Product Selected.

Thanks

My form

	<form action="" method="post" data-toggle="validator">
<div class="row">
<div class="col-md-4">
<div class="form-group">
<label>Item Name</label>
<select id="username" name="item_name" class="form-control inputs" data-error="Select Item" required>
<option value="">Chose Item</option>
<?php
$stmt = $pdo->query("
SELECT item_name FROM stocks
ORDER BY item_name ASC
");
while($row = $stmt->fetch(PDO::FETCH_ASSOC)) {
$item_name = $row['item_name'];
echo "<option value=\"$item_name\">
$item_name
</option>";
}
?>
</select>
<div class="help-block with-errors"></div>
</div>
</div>
<div class="col-md-2">
<div class="form-group">
<label>Unit Price</label>
<input type="number" class="form-control" name="item_price">
<div class="help-block with-errors"></div>
</div>
</div>
<div class="col-md-2">
<div class="form-group">
<label>Item Quantity</label>
<input type="number" class="form-control" name="item_qty" required data-error="Stock Quantity is missing">
<div class="help-block with-errors"></div>
</div>
</div>
<div class="col-md-2">
<div class="form-group">
<label>Amount</label>
<input type="number" class="form-control" name="amount" >
<div class="help-block with-errors"></div>
</div>
</div>
</div>
<br>
<span class="input-group-btn">
<input name="send" type="submit" class="btn btn-danger btn-form display-4 rounded" value="ADD">
</span>
</form>
	

Edited May 4, 2019 by I-AM-OBODO

Hi there i have a big issues which is starting to cause me lots of stress. I have two tables one which is products and contains the following below and the other which is additionalCategories which the contains is also below.

products

    id                    
    name                                
    image1                         
    image2                            
    image3                            
    image4                         
    image5                            
    description                         
    department                            
    category                            
    subcategory                         
    Price

additonalCategories

         id                     
    departmentID                         
    categoryID                         
    subcategoryID                           
    productID

i have made a products upload script to my site where i can add products too it saves the category and subcategory id's in the fields above then if i wish to add the product to additional categories i do so and again this adds all the data to the addiotnalCategories table.

however i can seems to be able to display this on the view products page i tried the below code but get no luck

Code: [Select]
<?php
session_start();
$username=$_SESSION['username'];
include_once"../includes/db_connect.php";
$cat=$_GET['cat'];
?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Untitled Document</title>
</head>

<body>
<?php 
$query("SELECT products.name AS name, products.price AS price, addtionalCategories.productID AS productID FROM products, addtionalCategories WHERE category='$cat' AND products.id = addtionalCategories.productID");
while($fetch=mysql_fetch_object($query)){
echo"$fetch->name";
}
?>
</body>
</html>

i need a way in which on the page it check the category id then finds all the products that are saved in the additionalCategories table then to find the data saved in the products table such as the name and price etc

please any help will be appreciated thank you for reading
 

Hello,
I've created a page search to return results from my database inventory. On top of these results I would like to display a seperate list of five products not included in the search results but share the same sub_category_b (a column in my SQL table).

Posted below is my primary query of the database. If anyone can help me out with this it would be appreciated.
 
Code: [Select]
$colname_product = "-1";
if (isset($_GET['title'])) {
  $colname_product = $_GET['title'];
}
mysql_select_db($database_inventory, $inventory);
$query_product = sprintf("SELECT * FROM inventory WHERE item_name LIKE %s OR item_desc LIKE %s  ", GetSQLValueString("%" . $colname_product . "%", "text"),GetSQLValueString("%" . $colname_product . "%", "text"));
$product = mysql_query($query_product, $inventory) or die(mysql_error());
$row_product = mysql_fetch_assoc($product);

I've fooled around with this one for some time and haven't come up with a clear cut answer. Thank you in advance!