SELECT sellers.name AS 'Поставщик',
	   w.date_of_delivery AS 'Дата поставки', 
       SUM(wl.count) AS 'Общее количество заготовок', 
       SUM(wl.price) AS 'Общая стоимость поставленных заготовок'
FROM waybill w
JOIN waybill_lines wl ON w.waybill_id = wl.waybill_id
JOIN workpiece USING(work_id)
JOIN sellers USING(sel_id)
WHERE workpiece.material = '${material}'
GROUP BY sellers.name, w.date_of_delivery;