How do I check for a record?

OCMatt

I have an OC nightlife website with lots of pictures. I require people to input their email addresses to see the large pictures. When they do it sets a cookie so they don't have to do it every time. That part works fine. :-) But anytime someone clears cookies or goes to a new computer I get their email address again. So I have lots of duplicates.

How can I change the code I have to check the database first to see if the address exists. If it does, just set the cookie. If it does not, add the address then set the cookie. Here's the code I currently have. And I am a beginner so please be gentle. 😉 Process.php is the page that sets the cookie.

<?php require_once('Connections/connAddresses.php'); ?>
<?php
function GetSQLValueString($theValue, $theType, $theDefinedValue = "", $theNotDefinedValue = "")
{
$theValue = (!get_magic_quotes_gpc()) ? addslashes($theValue) : $theValue;

switch ($theType) {
case "text":
$theValue = ($theValue != "") ? "'" . $theValue . "'" : "NULL";
break;

case "long":
case "int":
$theValue = ($theValue != "") ? intval($theValue) : "NULL";
break;
case "double":
$theValue = ($theValue != "") ? "'" . doubleval($theValue) . "'" : "NULL";
break;
case "date":
$theValue = ($theValue != "") ? "'" . $theValue . "'" : "NULL";
break;
case "defined":
$theValue = ($theValue != "") ? $theDefinedValue : $theNotDefinedValue;
break;
}
return $theValue;
}

$editFormAction = $HTTP_SERVER_VARS['PHP_SELF'];
if (isset($HTTP_SERVER_VARS['QUERY_STRING'])) {
$editFormAction .= "?" . $HTTP_SERVER_VARS['QUERY_STRING'];
}

if ((isset($HTTP_POST_VARS["MM_insert"])) && ($HTTP_POST_VARS["MM_insert"] == "address_form")) {
$insertSQL = sprintf("INSERT INTO table_addresses (address) VALUES (%s)",
GetSQLValueString($HTTP_POST_VARS['address_field'], "text"));

mysql_select_db($database_connAddresses, $connAddresses);
$Result1 = mysql_query($insertSQL, $connAddresses) or die(mysql_error());

$insertGoTo = "process.php";
if (isset($HTTP_SERVER_VARS['QUERY_STRING'])) {
$insertGoTo .= (strpos($insertGoTo, '?')) ? "&" : "?";
$insertGoTo .= $HTTP_SERVER_VARS['QUERY_STRING'];
}
header(sprintf("Location: %s", $insertGoTo));
}
?>

weekender

use a select query to get all the rows matching the email, then use [man]mysql_num_rows[/man] to see if any rows were returned

OCMatt

It doesn't like mysql_num_rows. I changed the code and added some comments so I don't get lost. The error I'm getting is:

Warning: mysql_num_rows(): supplied argument is not a valid MySQL result resource

Here's the updated code. It's throwing the error below where I commented - // See if any results were returned

<?php require_once('Connections/connAddresses.php'); ?>
<?php

// Get the value - the email address from the form
function GetSQLValueString($theValue, $theType, $theDefinedValue = "", $theNotDefinedValue = "")
{
$theValue = (!get_magic_quotes_gpc()) ? addslashes($theValue) : $theValue;

$editFormAction = $HTTP_SERVER_VARS['PHP_SELF'];
if (isset($HTTP_SERVER_VARS['QUERY_STRING'])) {
$editFormAction .= "?" . $HTTP_SERVER_VARS['QUERY_STRING'];
}

// Create query to check DB for email address
$result = mysql_query("SELECT address FROM table_addresses WHERE address = '$theValue'");

// See if any results were returned
$num_rows = mysql_num_rows($result);

// if email is not in DB add the email to the DB and go to process.php
if ($num_rows = 0)
{

mysql_select_db($database_connAddresses, $connAddresses);
$Result1 = mysql_query($insertSQL, $connAddresses) or die(mysql_error());

// if email IS already in DB just go to process.php
if ($result > 0)

header("Location:process.php");
}
?>

weekender

ok first, a few pointers - don't post loads of code (try and keep it relevant) and if you post code, put it in the [ code ] [ /code ]tag (for html, sql, etc) or [ php ] [ /php ] for php code

right - that error is because your sql code is wrong, or isn't returning any rows. I don't think it's wrong, as it's fairly simple, so it must not be returning any rows. Echo the sql, so you can see how it looks with $theValue in, and try it in phpmyadmin or mysql command line

also another thing i spotted - a few lines below the sql call, the 'if' statement is a comparison so needs to be a double equals

if ($num_rows == 0)

adam