Ваш вопрос очень расплывчатый.
Я предполагаю, что вы говорите о сопоставлении первичного ключа с именем partnumber или чего-то подобного.1005 *
SELECT mp.partnumber
, mp.UPC_number
, wp.UPC_number
, pp.UPC_number
FROM metal_parts mp
INNER JOIN wood_parts wp ON (wp.partnumber = mp.partnumber)
INNER JOIN plastic_parts pp ON (pp.partnumber = mp.partnumber)
WHERE mp.partnumber = '8874578127';
Вы также можете сделать
SELECT mp.partnumber
, group_concat(mp.UPC_number) as metal_UPCs
, group_concat(wp.UPC_number) as wood_UPCs
, group(concat(pp.UPC_number) as plastic_UPCs
FROM metal_parts mp
INNER JOIN wood_parts wp ON (wp.partnumber = mp.partnumber)
INNER JOIN plastic_parts pp ON (pp.partnumber = mp.partnumber)
WHERE mp.partnumber = '8874578127'
GROUP BY mp.partnumber;
или
SELECT mp.partnumber
, concat_ws(','
, group_concat(mp.UPC_number)
, group_concat(wp.UPC_number)
, group(concat(pp.UPC_number)
) as UPCs_of_parts
FROM metal_parts mp
INNER JOIN wood_parts wp ON (wp.partnumber = mp.partnumber)
INNER JOIN plastic_parts pp ON (pp.partnumber = mp.partnumber)
WHERE mp.partnumber = '8874578127'
GROUP BY mp.partnumber;