SELECT *
FROM ((Item
INNER JOIN Category
ON Item.category_id = Category.category_id
)
INNER JOIN (
  SELECT b2.item_id AS item_id, MAX(b2.bid_id) AS bid_id
    FROM Bid b2 
   GROUP BY b2.item_id
  ) v1 ON v1.item_id = Item.item_id
)
INNER JOIN Bid
ON v1.bid_id = Bid.bid_id
;