最多发行的书籍在一天内

Question

我有两张桌子

1. Book（BookID，BookName）
2. 问题（BookID，IssueDate，Qty）

那么，我怎样才能找到指定日期的最大“已发行图书名称”。

Answer 1

select top 1 book.bookid, book.bookname from
(
  select bookid, sum(qty) as s
  from issue
  where issuedate = @issuedate
  group by bookid
) grp
inner join book 
  on book.bookid = grp.bookid
order by s

如果“最大”，则表示“在给定日期发出的数量最大的图书的名称”。

Answer 2

这样的事情：

select BookName from Book 
where BookId = (select BookId from Issue where IssueDate = @yourdate 
AND Qty = (select MAX(Qty) from  Issue))