-- Duplicate product barcodes were most probably not created on purpose,
-- so just keep the newer one for any duplicates
DELETE FROM product_barcodes
WHERE barcode IN (
	SELECT barcode
	FROM product_barcodes
	GROUP BY barcode
	HAVING COUNT(*) > 1
	)
	AND id NOT IN (
		SELECT MIN(id)
		FROM product_barcodes
		GROUP BY barcode
		HAVING COUNT(*) > 1
	);

CREATE UNIQUE INDEX ix_product_barcodes ON product_barcodes (
	barcode
);