从多对多关系中获取数据

Question

我想从书表中获取标题，并从主题表中获取某位作者所有书籍的主题名称

这是表关系

我试图从表中选择标题和主题，但我不能让它与多对多关系一起工作

SELECT book_title,subject_name FROM book,subject WHERE $subject_ID = subject_ID INNER JOIN book_author ON author_ID = '$author_ID'

我考虑过两个单独的查询，如果有人可以帮助我，我会很高兴。

Answer 1

试试这个：

SELECT book_title, subject_name
FROM Book
INNER JOIN Book_Author ON Book.book_ISBN = Book_Author.book_ISBN
INNER JOIN Author ON Book_Author.author_ID = Author.author_ID
INNER JOIN Subject ON Subject.subject_ID = Book.subject_ID
WHERE author_lastname = [whatever];

发布模特的好工作：）

编辑以符合确切需求：

SELECT book_title, subject_name
FROM Book
INNER JOIN Book_Author ON Book.book_ISBN = Book_Author.book_ISBN
INNER JOIN Subject ON Subject.subject_ID = Book.subject_ID
WHERE author_ID = '11';

顺便说一下，你有一个"Column 'author_ID' in where clause is ambiguous"，因为这一栏同时出现在Book_Author和Author中。这就是为什么你必须在它前面添加表名：）