SELECT w.date_of_delivery AS 'Дата поставки', 
	   name AS 'Поставщик',
       wl.count AS 'Количество', 
       wl.price * wl.count AS 'Общая сумма'
FROM waybill w
JOIN waybill_lines wl USING(waybill_id)
JOIN workpiece wp USING(work_id)
JOIN sellers USING(sel_id)
WHERE material = '${material}';