我想从书表中获取某个作者所有书籍的标题和主题表中的主题名称
这是表的关系
我试图从表格中选择标题和主题,但我无法让它处理多对多关系
SELECT book_title,subject_name FROM book,subject WHERE $subject_ID = subject_ID INNER JOIN book_author ON author_ID = '$author_ID'
我想提出两个单独的问题,如果有人能帮助我,我会很高兴。
最佳答案
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];
发布模型的工作做得很好 :)
根据具体需要进行编辑:
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,您有一个 “Column 'author_ID' in where clause is ambiguous”
因为该列同时出现在 Book_Author 和 Author 中。这就是为什么你必须在它前面加上表名:)
关于mysql - 从多对多关系中获取数据,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/11064275/