security tips

[Bob_PHP_Builder]

hey does anyone know were some good security tips are for creating php files..

ie making sure the following code will only run once

<?
/* Connect to database */

$db= mysql_connect("localhost", "", "");
mysql_select_db("", $db);

$lastrow = mysql_query("SELECT id 
FROM current 
ORDER BY id DESC LIMIT 1"); 

while($row= mysql_fetch_array($lastrow))
{
	$JOB= "BOB";
	$newlastrow= ($row["o_id"]+1);
	printf($BOB);
	printf($newlastrow);

}
$today = date("F j, Y, g:i a");                // Date to Print
echo "\n $today";  

$date = date("Ymd");          		// Date to Database                             

$sql= 	"INSERT INTO current
	VALUES ('$newlastrow', NULL, '$date', '1', '1')";
	mysql_query($sql);


?>

I appreciate it

[halojoy]

to use a session variable
will only allow 1 time per session
so if close down browser and start a new browser session
that variable will be lost, and this can be run again

to make a permanent indication,
we would need to store a variable flag in cookie or in database
or make some test of that last row in database

I dont know when or how often this INSERT should be allowed
because you have not told much details of it

<?php

// start session, and see if has been run before - redirect to index.php
session_start();
if( isset($_SESSION['been_run']) && $_SESSION['been_run'] == 1 ){
    header( 'location: index.php' );
    exit;
}


/* Connect to database */

$db= mysql_connect("localhost", "", "");
mysql_select_db("", $db);

$lastrow = mysql_query("SELECT id 
FROM current 
ORDER BY id DESC LIMIT 1"); 

while($row= mysql_fetch_array($lastrow))
{
	$JOB= "BOB";
	$newlastrow= ($row["o_id"]+1);
	printf($BOB);
	printf($newlastrow);

}
$today = date("F j, Y, g:i a");                // Date to Print
echo "\n $today";  

$date = date("Ymd");          		// Date to Database                             

$sql= 	"INSERT INTO current
	VALUES ('$newlastrow', NULL, '$date', '1', '1')";
	mysql_query($sql);

// set 'been run' flag variable
$_SESSION['been_run'] = 1;

?>