what are the details of the lots which are not used in any transactions?
select lot_details from lots except select t1.lot_details from lots as t1 join transactions_lots as t2 on t1.lot_id = t2.lot_id
what is the transaction id of lot id 11
select transaction_id from transactions_lots where lot_id = 11
what is the investor id of  transaction id 3?
select t1.investor_id from lots as t1 join transactions_lots as t2 on t1.lot_id = t2.lot_id where t2.transaction_id = 3