Help a PHP newbie

[rob893]

Ok, I am currently at Uni, with one of my units needing me to build a content management system. I have been learning PHP for about 2 months, so go easy on me.

 

So I was developing happily, I was able to use the CMS to add a product, edit that product and delete it. I load it up today to carry on working on it, but find that adding a product no longer works. I investigate further and find that the HTML form on the "Add a product" section's processing page (createProduct.php) is not receiving the values from the form using the $_POST method, therefore the mysql query was containing empty values. I found this confusing as I had not changed any of the code. So i investigate further, creating a test php page, copying the $_POST method into here and echoing the variables. And.. it worked. Even more confused, I delved deeper and found that the culprit for the $_POST method not working was one of my includes. connection.php.

 

Here is the connection.php include:

<?php
//1. Create database connection
$connection = mysql_connect("localhost", "root"); //No password on the DB yet as it is only local.
if (!$connection) {
	die("Database connection failed: " . mysql_error());
}

//2. Select database to use
$db_select = mysql_select_db("cms",$connection);
if (!$db_select) {
	die("Database selection failed: " . mysql_error());
}
?>

 

And here is createProduct.php;

<?php require_once("../includes/connection.php");?>
<?php require_once("../includes/functions.php");?>
<?php

?>
<?php
//Populating the variables with values from the HTML form
$Product_Name = mysql_prep($_POST['Product_Name']);
$Price = mysql_prep($_POST['Price']);
$Product_Information = mysql_prep($_POST['Product_Information']);
$category_id = $_POST['category'];

echo $Product_Name . "<br />";
echo $Price . "<br />";
echo $Product_Information . "<br />";
echo $category_id . "<br />";
?>
<?php
//Creating and submitting the mysql query
echo $category_id;
$query = "INSERT INTO tblProducts(
			Product_Name, Price, Product_Information, category_id
			) VALUES (
				'{$Product_Name}', {$Price}, '{$Product_Information}', {$category_id}
			)";

echo $query;
if (mysql_query($query, $connection)) {
	header("Location: createProduct.php");
	exit;
}
//error handling
else {
	echo "<p>Product creation failed.</p>";
	echo "<p>" . mysql_error() . "</p>";
}
?>
<?php mysql_close($connection); ?>

 

So my question is.. why, when suddenly loading it up today after a few days absence would the database connection code be conflicting ONLY ON THIS PAGE. editing and deleting a product still work.

 

I am truly stumped as this seems completley illogical and is probably something really obvious. Any help would be greatly appreciated.

[Muddy_Funster]

there's too many jumps here:

load it = it's not working

|--> copy content from createProduct.php to test.php, without changing page code or connection.php code = test.php working

    |-->decide connection.php is the problem, even though it works fine on two other different pages = Illogical 

 

how about filling in the blanks?

[rob893]

Sorry I will explain it in more detail.

 

To test it, I copied the contents of createProduct.php into a new file test.php. I stripped it down to the the bare minimum with only its contents being:

$Product_Name = mysql_prep($_POST['Product_Name']);
$Price = mysql_prep($_POST['Price']);
$Product_Information = mysql_prep($_POST['Product_Information']);
$category_id = $_POST['category'];

echo $Product_Name . "<br />";
echo $Price . "<br />";
echo $Product_Information . "<br />";
echo $category_id . "<br />";

 

This was just to see if there was an error in the way I was posting the contents of the form into this PHP page. The variables echoed with the correct values. I then started adding in the parts that I had stripped out ealier to see if I could locate the cause; creating the query, running the query and then the includes. The variables were correct on all occasions until I added in the connection include.

 

I get this error:

Notice: Undefined index: Product_Name in createProduct.php on line 27

Notice: Undefined index: Price in createProduct.php on line 28

Notice: Undefined index: Product_Information in createProduct.php on line 29

Notice: Undefined index: category in createProduct.php on line 30

 

INSERT INTO tblProducts( Product_Name, Price, Product_Information, category_id ) VALUES ( '', , '', )

Product creation failed.

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ' '', )' at line 4

 

This is what I was trying to explain earlier. Having the PHP code to create the DB connection causes my POST method to function incorrectly, so it runs a query with empty values thus throwing the error above.

 

The thing is, this only happens on adding a product, every other page with the connection include is fine, including adding a producing category which is exactly the same code except a different database table.

 

I hope this was easier to understand

[Muddy_Funster]

Could you post the top 20 - 25 lines of each of the other two pages and your form statement please?

[rob893]

HTML Form for adding a product:

<form action="createProduct.php" method="POST">
			<p>Product name:
				<input type="text" name="Product_Name" value="" id="Product_Name" />
				<br />
			<p>Product category: 
			<?
				//Selecting tblCategory data and looping it into an HTML forms drop down list
				$query = "SELECT * FROM tblCategory";
				$result = mysql_query($query);
				echo "<select name='category'>\n";
				while ($data = mysql_fetch_assoc($result)) {
					$name = $data['categoryName'];
					$id = $data['id'];
					echo "<option value=$id>$name</option>\n";
				}
				echo "</select>\n"; 
			?>
			<p>Price: 
				<input type="text" name="Price" value="" id="Price" />
			</p>
			<p>Product Information:</p>
			<textarea cols="50" rows="4" name="Product_Information" id="Product_Information"></textarea>

			<br />
			<br />
			<input type="submit" value="Add Product"/>
			<input type=button onClick="parent.location='http://localhost/458691/CMS/product.php'" value='Cancel'>

 

Adding a product Category:

<?php require_once("../includes/connection.php");?>
<?php require_once("../includes/functions.php");?>
<?php
$Category_Name = mysql_prep($_POST['Category_Name']);

echo $Category_Name . "<br />";

$query = "INSERT INTO tblCategory(
			CategoryName
			) VALUES (
				'{$Category_Name}'
			)";

echo $query;
if (mysql_query($query, $connection)) {
	header("Location: category4.php");
	exit;
}
//error handling
else {
	echo "<p>Product creation failed.</p>";
	echo "<p>" . mysql_error() . "</p>";
} 
?>
<?php mysql_close($connection); ?>

 

And editing a product:

<?php error_reporting (E_ALL ^ E_NOTICE);  //Hide undefined variable warning ?>
<?php require_once("../includes/connection.php");?>
<?php require_once("../includes/functions.php");?>
<?php
//Start a session to allow easy transfer of numerous variables over a number of PHP pages
session_start();

$id = $_SESSION['id'];

//creating the variables with updated values from the HTML form
$Product_Name = mysql_prep($_POST['Product_Name']);
$Price = mysql_prep($_POST['Price']);
$Product_Information = mysql_prep($_POST['Product_Information']);

//Creating the update query to update values in the product table
$query = "UPDATE tblProducts SET
			Product_Name = '{$Product_Name}',
			Price = {$Price},
			Product_Information = '{$Product_Information}'
		WHERE id = {$id}";
echo $query;


if (mysql_query($query, $connection)) {
	header("Location: Product4.php");
	exit;
}
//error handling
else {
	echo "<p>Product update failed.</p>";
	echo "<p>" . mysql_error() . "</p>";
}

?>
<?php mysql_close($connection); ?>