Php MySQL如何通过一个查询从不同的表中获得两个结果

我有以下表格：

---

表名----|表字段

图书--------------------图书id、图书名称

作者-----------作者id，作者姓名

图书作者-作者id，图书id

用户------------------用户id、用户名

注释----------注释id，注释

评论|用户|评论| id、用户id、图书id、日期

---

我需要显示书名、作者以及为这本书发布的所有评论（我需要显示用户名、日期、评论）。 我可以用两个不同的sql查询来完成，但我不知道如何用一个查询来完成。 以下是两个问题：

SELECT * FROM books
INNER JOIN books_authors
ON books.book_id=books_authors.book_id
INNER JOIN authors
ON books_authors.author_id=authors.author_id
WHERE books.book_id=7

这个函数返回id=7的书的名称和作者

SELECT `user_name`, `comment`, `date`
FROM comments_users
INNER JOIN comments ON comments_users.comment_id = comments.comment_id
INNER JOIN users ON comments_users.user_id = users.user_id
WHERE comments_users.book_id=7

这将返回用户名、注释和注释发布日期。

---

有谁能解释一下，我如何将它们合并到一个查询中？提前感谢

您不能将两个查询中的所有表合并起来吗

SELECT `books.book_id`, `books.book_title`, `comments_users.user_name`,
`comments_users.comment`, `comments_users.date` 
FROM books
INNER JOIN books_authors ON books.book_id=books_authors.book_id
INNER JOIN authors ON books_authors.author_id=authors.author_id
INNER JOIN comments_users ON comments_users.book_id = books.book_id
INNER JOIN comments ON comments_users.comment_id = comments.comment_id
INNER JOIN users ON comments_users.user_id = users.user_id
WHERE books.book_id=7

---

希望这就是您试图实现的目标。

您不能将两个查询中的所有表合并起来吗

SELECT `books.book_id`, `books.book_title`, `comments_users.user_name`,
`comments_users.comment`, `comments_users.date` 
FROM books
INNER JOIN books_authors ON books.book_id=books_authors.book_id
INNER JOIN authors ON books_authors.author_id=authors.author_id
INNER JOIN comments_users ON comments_users.book_id = books.book_id
INNER JOIN comments ON comments_users.comment_id = comments.comment_id
INNER JOIN users ON comments_users.user_id = users.user_id
WHERE books.book_id=7

---

希望这就是您试图实现的目标。

您不能将两个查询中的所有表合并起来吗

SELECT `books.book_id`, `books.book_title`, `comments_users.user_name`,
`comments_users.comment`, `comments_users.date` 
FROM books
INNER JOIN books_authors ON books.book_id=books_authors.book_id
INNER JOIN authors ON books_authors.author_id=authors.author_id
INNER JOIN comments_users ON comments_users.book_id = books.book_id
INNER JOIN comments ON comments_users.comment_id = comments.comment_id
INNER JOIN users ON comments_users.user_id = users.user_id
WHERE books.book_id=7

---

希望这就是您试图实现的目标。

您不能将两个查询中的所有表合并起来吗

SELECT `books.book_id`, `books.book_title`, `comments_users.user_name`,
`comments_users.comment`, `comments_users.date` 
FROM books
INNER JOIN books_authors ON books.book_id=books_authors.book_id
INNER JOIN authors ON books_authors.author_id=authors.author_id
INNER JOIN comments_users ON comments_users.book_id = books.book_id
INNER JOIN comments ON comments_users.comment_id = comments.comment_id
INNER JOIN users ON comments_users.user_id = users.user_id
WHERE books.book_id=7

---

希望这就是您试图实现的目标。

此排列的查询应该足够了，它将根据您的需要显示结果：

SELECT books.book_title, authors.author_name, comments.comment FROM books
INNER JOIN books_authors
ON books.book_id=books_authors.book_id
INNER JOIN authors
ON books_authors.author_id=authors.author_id
LEFT JOIN comments_users ON comments_users.book_id = books.book_id
INNER JOIN comments ON comments_users.comment_id = comments.comment_id
INNER JOIN users ON comments_users.user_id = users.user_id
WHERE books.book_id=7

---

此排列的查询应该足够了，它将根据您的需要显示结果：

SELECT books.book_title, authors.author_name, comments.comment FROM books
INNER JOIN books_authors
ON books.book_id=books_authors.book_id
INNER JOIN authors
ON books_authors.author_id=authors.author_id
LEFT JOIN comments_users ON comments_users.book_id = books.book_id
INNER JOIN comments ON comments_users.comment_id = comments.comment_id
INNER JOIN users ON comments_users.user_id = users.user_id
WHERE books.book_id=7

---

此排列的查询应该足够了，它将根据您的需要显示结果：

SELECT books.book_title, authors.author_name, comments.comment FROM books
INNER JOIN books_authors
ON books.book_id=books_authors.book_id
INNER JOIN authors
ON books_authors.author_id=authors.author_id
LEFT JOIN comments_users ON comments_users.book_id = books.book_id
INNER JOIN comments ON comments_users.comment_id = comments.comment_id
INNER JOIN users ON comments_users.user_id = users.user_id
WHERE books.book_id=7

---

此排列的查询应该足够了，它将根据您的需要显示结果：

SELECT books.book_title, authors.author_name, comments.comment FROM books
INNER JOIN books_authors
ON books.book_id=books_authors.book_id
INNER JOIN authors
ON books_authors.author_id=authors.author_id
LEFT JOIN comments_users ON comments_users.book_id = books.book_id
INNER JOIN comments ON comments_users.comment_id = comments.comment_id
INNER JOIN users ON comments_users.user_id = users.user_id
WHERE books.book_id=7

---

MySQL不是sql Server MySQL不是sql Server MySQL不是sql Server MySQL不是sql Server虽然我自己知道怎么做（你的答案几乎相同），但我认为这是最好的答案，我认为这是最好的答案。虽然我自己知道怎么做（你的答案几乎相同），但我认为这是最好的答案。尽管我自己知道怎么做（你的答案几乎相同），我认为这是最好的答案。