test.php

<?php
// Sample data from data.csv
//line 1, product 1, feature 1
//line 2, product 1, feature 2
//line 3, product 1, feature 3
//line 4, product 2, feature 1
//line 5, product 3, feature 1

class Product {
	// Product lines until we save
	protected $data;

	public function __construct() {
		// Make sure $this->data is an array
		if (empty($this->data)) {
			$this->data = array();
		}
	}
	
	public function process($data) {
		// First product line ever or
		// first product line after save
		if (empty($this->data)) {
			$this->data[] = $data;
			return;
		}
		
		// We can compare stuff now
		$processResult = $this->import($data);
		
		// Empty $this->data after saving product to DB
		if ($processResult) {
			$this->data = array();
		}
		$this->data[] = $data;
	}

	public function import($data) {
		$result = false;
		
		if (!empty($this->data)) {
			$lastProduct = $this->data[ sizeof($this->data) - 1 ];
			if ($lastProduct[1] <> $data[1]) {
				echo "Saving " . $lastProduct[1] . " to the database\n";
				$this->dbInsert();
				$result = true;
			}
		}

		return $result;
	}

	public function dbInsert() {
		foreach ($this->data as $item) {
			print "INSERT INTO PRODUCTS $item[0], $item[1], $item[2]\n";
		}
	}

	public function __destruct() {
		if (!empty($this->data)) {
			$lastItem = $this->data[ sizeof($this->data) - 1 ];
			$emptyItem = array();
			foreach ($lastItem as $key => $value) {
				$emptyItem[$key] = null;
			}
			$this->process($emptyItem);
		}
	}
}

$fh = fopen('data.csv', 'r');
if (!$fh) {
	die("Failed to open CSV for reading");
}
$product = new Product();
while (($data = fgetcsv($fh)) !== false) {
	$product->process($data);
}

fclose($fh);

?>