php - parse an rss feed and update/insert/delete rows -

i'm trying parse multiple rss feeds , if change, update records in mysql table.

currently, have script inserts items of rss feeds (just post in url in form , submit). inserts following table: title, rss_url, description, price, discount, total

this works well.

the next part script updates rows if change in rss, changes if price or discount update. works great

what i'm looking is: if item in rss feed removed, script needs detect , delete row or insert flag table been deleted...

my code quite long winded:

$result = mysql_query("select * easy_contents"); while($row = mysql_fetch_array($result)) {  $articles = array(); $easy_url = $row['rss_url'];  $rawfeed = file_get_contents($easy_url); $xml = new simplexmlelement($rawfeed);   $channel = array(); $channel['title']       = $xml->channel->title; $channel['link']        = $xml->channel->link; $channel['description'] = $xml->channel->description;   foreach ($xml->channel->item $item) { $article = array(); $article['title'] = $item->title; $article['link'] = $item->link; $article['description'] = (string) trim($item->description);  //strip out html tags $item->description = str_replace('<table><tr><td width="110">','', $item->description); $item->description = str_replace('</table>','', $item->description); $item->description = str_replace('</td>','', $item->description); $item->description = str_replace('<td>','', $item->description); $item->description = str_replace('<br />','', $item->description); $item->description = str_replace('<b>','', $item->description); $item->description = str_replace('</b>','', $item->description); $item->description = str_replace('</tr>','', $item->description);  //find url encoded £ signs , find string after //string price preg_match_all('/&#xa3;([0-9.]+)/', $item->description, $results); foreach ($results $k => $v) { }  //find url encoded £ sign , append price $all = '&#xa3;'.$v[0]; $price_stripped = str_replace($all, '', $item->description); $desc = preg_match('/&#xa3;([0-9.]+)/', $item->description);  //find discount deleviry cost rss using ~#&pound;number //this discount preg_match_all('/~#&pound;([0-9.]+)/', $item->description, $discount); foreach ($discount $d => $disc) { str_replace("~#&pound;","", $disc[0]); }  //find remaining £price , delivery cost //this delivery_cost preg_match_all('/&pound;([0-9.]+)/', $item->description, $delivery_cost); foreach ($delivery_cost $del => $deliv) {  }   //find | char , find string after //this retailer_message preg_match_all('/\|(.*?)\./',$item->description,$match);            foreach ($match $rel => $retail) {  $retail[0] = str_replace("| ","", $retail[0]); $retail_mess = str_replace(" on","on", $retail[0]);   }      $total = $v[0] + $deliv[0] - $disc[0];   $sql = "update easy_contents set delivery_cost = '$deliv[0]', price = '$v[0]', total = '$total' rss_url = '$row[rss_url]' , title = '$item->title' , description = '$price_stripped' ";  if(!$query = mysql_query($sql)) {      echo "error on line ".__line__.". ".mysql_error().".<br />\nquery: ";      exit;  }  echo "query ok. <br />\nupdated rows: ".mysql_affected_rows().".<br />\nquery: ";    }      } 

this updates row in database depending if rss item changes.

can provide snippet of how i'd detect if item in rss deleted , php/mysql delete such row table?

thank you

if replacing data new data rss feed won't work you, run through few steps:

1. query db. parse array id
2. parse rss array id.
3. compare arrays. difference id's delete db.
4. loop through difference array , delete.

i similar on app wrote. it's long solution, once bugs out works well.