Sql 试图生成一个表，其中一本书的成本高于所有书的平均成本

试图生成一个表，其中一本书的成本高于所有书的平均成本

SELECT book_num, book_title, book_cost
FROM (SELECT book_num, book_title, book_cost, Avg(book_cost) AS AVGPRICE
      FROM book
      GROUP BY book_num, book_title, book_cost)
WHERE book_cost > AVGPRICE
ORDER BY book_title;

试试这个（我使用了无处不在的酒吧数据库）

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DECLARE @avgprice money;

SET @avgprice = (SELECT  Avg(price) FROM titles);   

SELECT title, price, @avgprice as AveragePrice 
FROM titles 
WHERE price > @avgprice ORDER BY title;

SELECT book_num, book_title, book_cost
FROM book
WHERE book_cost > (SELECT  Avg(book_cost) FROM book)
ORDER BY book_title;