SELECT *
FROM Book b
WHERE b.book_id IN (SELECT DISTINCT(c.book_id)
FROM Copy c
WHERE c.copy_id IN (SELECT copy_id
FROM Loan
WHERE Datediff(DAY, Getdate() - 180, loan_date) > 180)
GROUP BY c.copy_id
HAVING Count(copy_id) > 10)
當我運行此查詢時,出現錯誤。列在選擇列表中無效
「Column'Copy.Book_id'在選擇列表中無效,因爲它不包含在聚合函數或GROUP BY子句中。」
的[?什麼是「無效,未包含在聚合函數」消息的意思(可能重複的HTTP ://stackoverflow.com/questions/18258704/what-does-the-invalid-not-contained-in-either-an-aggregate-function-message-m) – Tanner 2015-04-29 13:38:13