我在书籍和作者之间建立了多对多关系。
我怎样才能得到所有不止一个作者的书？ (在下面的示例数据库中，这将为 0)
书籍表:
+--------+------------------+
| BookId | Book |
+--------+------------------+
| 1 | Wizard of Oz |
| 2 | Huckleberry Finn |
+--------+------------------+
作者表:
+----------+------------------+
| AuthorId | Author |
+----------+------------------+
| 1 | Mark Twain |
| 2 | Lyman Frank Baum |
+----------+------------------+
联结表:
+--------+----------+
| BookId | AuthorId |
+--------+----------+
| 1 | 2 |
| 2 | 1 |
+--------+----------+
最佳答案
你可以通过计数来使用分组
select books.* from books
inner join junction on books.id = junction.bookid
group by bookId
having count(distinct AuthorId ) > 1
关于mysql - SQL 选择超过 1 个联结点的位置，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/59019796/