Loosing DB connection in LOGIN form

[spstieng]

Hi,

I'm trying to create a simple login form!

Here is my INDEX.PHP

  include_once('config.php');

  include (DIR_INCLUDE.'basicHeader.inc.php');
  include_once(DIR_INCLUDE.'init.php'); //initializes the DB

echo '  

  <form name="form1" method="post" action="authentication.php">
	<table class="loginFrame" summary="Innloggings side">
	<tr>
	     <td>Username</td>
		 <td>
           <input class="loginInput" name="username" type="text" size="12" maxlength="10" />
	     </td>
	 </tr>

 <tr>
  <td>Password </td>
  <td> 
    <input class="loginInput" name="password" type="password" size="12" maxlength="10" />
  </td>
 </tr>

 <tr>
   <td colspan="2">
     <input name="Login" type="submit" value="Login">
   </td>
 </tr>
</table>
  </form>';

  include (DIR_INCLUDE.'basicFooter.inc.php');	
?>

So far so good.

Now, if I include this at the end in the INDEX.PHP, I get the expected result:

	$result = @mysql_query('SELECT empFname, empLname, empUsrName, empPsw FROM employee WHERE empUsrName="test"') or die (mysql_error());
	$row = mysql_fetch_array($result);

echo $row['empFname'];

If I include exactly the same lines of code at the TOP of authentication.php I get the following error msg: "No Database Selected"

Why do I loose my DB info / connection when I get the authentication.php file? I have intentionally set empUsrName="test" (for testing purpose).

[swr]

You need to connect to the database at the start of every page that uses the database. The reason for this is, HTTP is basicly stateless. When your browser requests a page, it makes a connection to the web server, requests a page, and closes the connection. When it request another page, it does the same thing. There is no continuity.

You can use sessions to preserve some variables, but not database connections. Database connections are owned by the web server process, and when you connect to retrieve the next page, there is no guarantee you will connect to the same web server process as you did before (most web servers use multiple processes or multiple threads so that they can serve multiple browsers simultaneously).

There's also persistent connections, but you still have to call mysql_pconnect at the start of every page that uses the database.