去拿收据上的东西

SELECT receipts_body.receipt_id,items.id,items.title FROM receipts_body
LEFT JOIN items ON items.id = receipts_body.item_id
ORDER BY receipt_id

获取主要类别的收据

SELECT receipts_body.receipt_id,items.id,items.title FROM receipts
LEFT JOIN items ON items.id = receipts_body.item_id
WHERE receipt_id IN (SELECT receipt_id FROM receipt_body WHERE item_id = 771013)
ORDER BY receipt_id

获取小类收据

SELECT receipts_body.receipt_id,items.id,items.title FROM receipts
LEFT JOIN items ON items.id = receipts_body.item_id
WHERE receipt_id IN (SELECT receipt_id FROM receipt_body WHERE item_id = 771012)
ORDER BY receipt_id