mysqlクエリ：行われたすべての支払いの概要と日付ごとの請求書の合計を表示します

select
  x.date,
  sum(x.invoiceTotal) as invoiceTotal,
  sum(x.paymentsMade) as paymentMade
from
 (select
   i.date, 
   sum(i.rate * i.quantity /*?*/) as invoiceTotal,
   null as paymentMade    
 from
   invoice i
   inner join invoiceitem ii on ii.invoiceId = i.invoiceId
 group by
   i.date
 union all
 select
   p.date,
   null as invoiceTotal,
   sum(p.amount) as paymentMade    
 from
   payment p
 group by
   p.date) x
group by
  x.date
order by
  x.date