獲取所有超過X個列值的行

Question

我在MySQL數據庫中有一個帶有標題和作者列的書表。 我需要選擇表中具有X個以上作者的Author的所有書籍。

這是所需輸出的示例：

| Author        | Title                |
|---------------|----------------------|
| Dan Brown     | Angels and Demons    |
| Dan Brown     | The Da Vinci Code    |
| Robert Ludlum | The Bourne Identity  |
| Robert Ludlum | The Bourne Supremacy |

我可以通過一個簡單的小組並有條件地為每個作者獲得一本書：

SELECT * FROM books
GROUP BY author
HAVING count(author) > 1
ORDER BY author;

給出以下輸出：

| Author        | Title                |
|---------------|----------------------|
| Dan Brown     | Angels and Demons    |
| Robert Ludlum | The Bourne Identity  |

如何獲得作者擁有超過X本書的書籍清單？

Answer 1

您可以將查詢用作子選擇 ：

SELECT * FROM books WHERE Author IN (
    SELECT Author
    FROM books
    GROUP BY Author
    HAVING COUNT(Author) > 1
) ORDER BY Author, Title;

如果您想獲得每個作者的簡單（逗號分隔）書籍清單，您還可以使用GROUP_CONCAT使用以下解決方案：

SELECT Author, GROUP_CONCAT(Title) AS title_list
FROM books
GROUP BY Author
HAVING COUNT(Author) > 1
ORDER BY Author;

演示： http : //sqlfiddle.com/#!9/10d80f/2/0

Answer 2

您應該可以使用子查詢 ：

SELECT * FROM books
WHERE author IN (
  SELECT author
    FROM books
    GROUP BY author
    HAVING COUNT(author) > 1
  )

Answer 3

也許嘗試使用...

SELECT [Author] , [Title]
  FROM [books] b
  where [Author] in 
  (select Author from [books] group by [Author]
       having count(Author) >1) 

Answer 4

一個非常簡單的查詢將如下所示

SELECT books.Title
FROM (SELECT Count(books.Author) AS CountOfAuthor, books.Author AS A
FROM books
GROUP BY books.Author )  AS bookByAuthor INNER JOIN books ON bookByAuthor.A = 
books.Author
WHERE (((books.Author)=[bookByAuthor].[A]));

希望這可以幫助