How to pass a variable between php pages

php_beginner_83

Hi All

I'm having problems trying to pass a variable between php pages. Previously, I have done it by passing the value through the url but I can't do that this time. I have a webpage (script A) and another page (script 😎. I include script B in the content <div> section of script A using PHP include() and I want to pass a variable from script A to script B.
Is there a way I can do this?

Thank you.

bradgrafelman

If you just set the variable in the global scope of script A, you should be able to access it in script B's global scope. Example:

scriptB.php

<?php
echo "Hello, $user!";
?>

scriptA.php

<?php
$user = "foobar";

echo "<div>";
include 'scriptB.php';
echo "</div>";
?>

In other words, the two scripts will share the same global scope.

php_beginner_83

The variable I'm trying to access in both scripts is $getValue.
I've tried what you suggested but it isn't working, so I must be doing something wrong.
This is my script A...

<?php
$getValue = $_GET['place'];
?>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<meta http-equiv="Content-Language" content="zh">

<title>My Travel Website</title>
<link href="americanStyle.css" rel="stylesheet" type="text/css" media="screen" />
</head>
<body>
<div id="wrapper">
	<div id="americaHeader">
		<div id="logo">
			<h1><a href="#">My American Adventures</a></h1>
		</div>
	</div>
	<!-- end #header -->
	<div id="menu">
		<ul>
			<li><a href="#">Home</a></li>
			<li><?php echo"<a href=America1.php?page=photo>"; ?>Photos</a></li>
			<li><a href="#">Sights</a></li>
			<li><a href="#">Dos & Donts</a></li>
		</ul>
	</div>
	<!-- end #menu -->
	<div id="page">
		<div id="content">

		<?php

		if ($getValue == 1)
		{
			$content = 'SanFranContent.htm';
		}
		if ($getValue == 2)
		{
			$content = 'NewYorkContent.htm';
		}
		if ($getValue == 3)
		{
			$content = 'MemphisContent.htm';
		}
		if ($getValue == 4)
		{
			$content = 'NashvilleContent.htm';
		}

// you build an array for the pages you have. 
$index = array( "main" => $content,
				"photo" => "DisplayAlbums.php" ); 

if ( !empty( $_GET["page"] ) ) 
{ 
   $page = $_GET["page"]; 
   if ($page == "photo")
	{

	$page = $_GET["page"];
	$place = isSet( $getValue ) ? $getValue : 'Default';

}
}

if ( array_key_exists( $page , $index ) ) 
{
    include( $index[$page] ); 
} 


?> 

	</div>

</div>


</div>
</body>
</html>

And this is script B...

<?php

$username = "root";
$password = "";
$hostname = "localhost"; 


//connection to the database
$dbhandle = mysql_connect($hostname, $username, $password) 
  or die("Unable to connect to MySQL");
//echo "Connected to MySQL<br>";

$selected = mysql_select_db("MyWebsite",$dbhandle) 
  or die("Could not select examples");

$result = mysql_query("SELECT * FROM albums WHERE Place=\"$getValue\"");
$row = mysql_fetch_array($result);

echo "<table border='0' cellspacing='50'>";

$ID = $row['ID'];
$title = $row['Title'];
$table1 = "<td><a href=America1.php?link=$title>" . $row['Title'] . "</a></td>" . $table1;
$thumb = "images\\" . $row['AlbumCover'];
$table2 = "<td><img src=\"$thumb\"></td>" . $table2;
$table3 = "<td>" . $row['Description'] . "</td>" . $table3;
echo "<td><a href=AmericaPhotos.php?link=$title&ID=$ID&place=$getValue>" . $row['Title'] . "</a><br/><br/><img src=\"$thumb\"><br/><br/>" . $row['Description'] . "</td>";

while($row = mysql_fetch_array( $result ))
{

$ID = $row['ID'];
$title = $row['Title'];
$table1 = "<td><a href=DatabaseConnection.php?link=$title>" . $row['Title'] . "</a></td>" . $table1;
$thumb = "images\\" . $row['AlbumCover'];
echo "thumb " .$thumb;
$table2 = "<td><img src=\"$thumb\"></td>" . $table2;
$table3 = "<td>" . $row['Description'] . "</td>" . $table3;

echo "<td><a href=AmericaPhotos.php?link=$title&ID=$ID&place=$getValue>" . $row['Title'] . "</a><br/><br/><img src=\"$thumb\"><br/><br/>" . $row['Description'] . "</td>";
}


echo "</table>";

bradgrafelman

For one, you can just stick with using the $_GET array, especially since it's a superglobal variable.

Second, string values in SQL queries are denoted by single quotes, not double quotes.

Third, your script is vulnerable to SQL injection attacks; user-supplied data should never be placed directly into a SQL query. Instead, it must first be sanitized with a function such as [man]mysql_real_escape_string/man.

EDIT: I forget that MySQL differs from other DBMS in the way it denotes identifiers. The double quotes in the query aren't likely causing a problem. Either way, try echo'ing out the query to see what it looks like.

php_beginner_83

I tried using the $GET['place'] but it didn't work. I'm assuming I just put this line of code in script B.

I don't understand why it's not working for me. Would it have anything to do with the fact that this value initially comes from a link the user has clicked and is passed through the url?
The way my website works is from the first page there is a list of cities. When the user clicks a city a new page opens and the ID of this city is passed through the url to this new page. This ID is the value I'm interested in. I use the code, $GET['place'], to get this value. On this page (which I previously called script A) is an intro to the city and a menu bar. On the menu bar there is a link, 'Photos'. When the user clicks this link, a page (previously script 😎 is displayed in the content section of script A. This is done using an include().

Thanks for the tip regarding the SQL query and mysql_real_escape_string(). I'm still new to this and have a lot to learn.

I really appreciate your help.