MySQL matching and non-matching combinations - php

Question

I'm trying to create conditional statements for license validating. I have 3 parameters purchase code, item id and website URL. I want to check if they together or partially matches data in my database rows and insert if it does not exist. So I have to create SQL query or queries to do this, but I couldn't figure out what is the cleanest/efficient way. Look at the code itself and you will understand what I'm trying to do.
<?php
if (isset($_GET['purchasecode']) && isset($_GET['itemid']) && isset($_GET['website'])) {
$purchasecode = $mysqli->real_escape_string($_GET['purchasecode']);
$website = $mysqli->real_escape_string($_GET['website']);
$itemid = $mysqli->real_escape_string($_GET['itemid']);
require_once 'class-verify.php';
$access_token = 'MyAccessTokenHere';
$purchase = new EnvatoPurchaseCodeVerifier($access_token);
$verified = $purchase->verified($purchasecode);
// Verified that user have purchased one of our items
if ($verified) {
$item_id = $verified->item->id;
$item_name = $verified->item->name;
$buyer = $verified->buyer;
$license = $verified->license;
$amount = $verified->amount;
$sold_at = $verified->sold_at;
$supported_until = $verified->supported_until;
$query = $mysqli->query("SELECT * FROM PurchaseCodes WHERE Code='".$purchasecode."' AND ItemID='".$item_id ."' AND Website='".$website."'");
if (/* puchase code, item id and website URL exist/matches */) {
echo 'License is already active!';
} elseif (/* puchase code and item id matches but website URL is different */) {
echo 'License is already actived on another website!';
} elseif ($item_id != $itemid) {
echo 'This purchase code is for our another item';
}else {
// insert into database if not already exists
$mysqli->query("INSERT IGNORE INTO PurchaseCodes (Code, ItemID, Website) VALUES ('$purchasecode', '$item_id', '$website')");
echo 'License is successfully activated!';
}
} else {
echo 'Purchase code is invalid!';
}
}
?>

Answer 1

Maybe smt like this would help:
$valid_license_sql = "SELECT
CASE WHEN Code='".$purchasecode."' THEN 1 ELSE 0 END as purchasecode,
CASE WHEN ItemID='".$item_id ."' THEN 1 ELSE 0 END as itemid,
CASE WHEN Website='".$website."' THEN 1 ELSE 0 END as website,
CASE WHEN Code='".$purchasecode."' AND ItemID='".$item_id ."' AND Website='".$website."' THEN 1 ELSE 0 END as license
FROM PurchaseCodes";
$query = $mysqli->query($valid_license_sql);
$proper= $query->fetch_assoc();
if ( $proper['license'] ) {
echo 'License is already active!';
} elseif ( $proper['purchasecode'] && $proper['itemid'] && !proper['website']) {
echo 'License is already actived on another website!';
} elseif ( !$proper['itemid'] ) {
echo 'This purchase code is for our another item';
}else {
// insert into database if not already exists
$mysqli->query("INSERT IGNORE INTO PurchaseCodes (Code, ItemID, Website) VALUES ('$purchasecode', '$item_id', '$website')");
echo 'License is successfully activated!';
}
If you have more rows at table simply loop through result set.