好的，我有一个Books的表，每本书都有现在相关的2 fileds：Title&Author，如何显示拥有一本以上书籍的作者的书名？我试过
SELECT Title, Author, COUNT(Author) AS Books FROM BOOK
GROUP BY Author HAVING COUNT(Author) >= 2;
但这只给了我每个作者一个标题，作者和作者拥有的书籍的amt。例如
The Sun Also Rises | Hemingway | 2
Foundation | Asimov | 2
等等。
如何解决？子查询也可以使用
像这样使用group_concat：-
SELECT group_concat(Title) as Title, Author, COUNT(Author) AS Books
FROM BOOK GROUP BY Author HAVING COUNT(Author) >= 2;
运行此查询
您可以在子查询中确定至少有2本书的作者，然后获得他们的图书列表：
SELECT book.Title, book.Author
FROM book
INNER JOIN (SELECT Author FROM BOOK GROUP BY Author HAVING COUNT(Author) >= 2) t
ON book.Author=t.Author;
SELECT b.title,b.author,c.cnt FROM books AS b INNER JOIN
(SELECT author,COUNT(*) AS cnt FROM books GROUP BY author) AS c
ON b.author = c.author
WHERE c.cnt > 1;
适用于任何数据库系统，而不仅仅是mysql。