<?php
/**
 * Created by PhpStorm.
 * User: nixelce
 * Date: 21.10.2017
 * Time: 14:09
 */
$table_name = 'testtable';
$link = pg_pconnect("host=localhost port=5432 dbname=testDB user=postgres password=")
    or die("Ошибка " . pg_errormessage());

$query ='SELECT * FROM '. $table_name;
$result = pg_query($link, $query) or die("Ошибка " . pg_errormessage($link));

while ($row = pg_fetch_assoc($result)) {
    $name = $row['name'];
    $rate = $row['rate'];
    $date = $row['date'];
    print ($name."   ");
    print ($rate ."   ");
    print ($row .  "\n");
}

$rss = "http://www.nationalbank.kz/rss/rates_all.xml";

$xmlstr = @file_get_contents($rss);
if($xmlstr===false)die('Error connect to RSS: '.$rss);
$xml = new SimpleXMLElement($xmlstr);
if($xml===false)die('Error parse RSS: '.$rss);

$pubDate = DateTime::createFromFormat('d.m.y', (string)$xml->channel->item->pubDate);
$pubDate = $pubDate->format('Y-m-d');

$result = pg_query($link, 'SELECT * FROM ' . $table_name . ' WHERE date = \'' . $pubDate . '\'');

if (!pg_num_rows($result))
{
    foreach ($xml->channel->item as $item)
    {
        $pubDate = DateTime::createFromFormat('d.m.y', (string)$item->pubDate);
        $pubDate = $pubDate->format('Y-m-d');
        $query = 'INSERT INTO ' . $table_name . '(date, name, rate) VALUES (\'' . $pubDate . '\', \'' . (string)$item->title . '\', ' . (double)$item->description . ')';
        $ins = pg_query($link, $query);
    }
}
else print("Данные за этот день уже загружены\n");
if (pg_close())
{
    print ("Соединение закрыто");
};