Question

用于以下架构：

Publisher (name, phone, city), PK: name.
Book (ISBN, title, year, published_by, previous_edition, price), PK: ISBN, FK: published_by refs Publisher, previous_edition refs Book.
Author (SSN, first_name, last_name, address, income), PK: SSN.
Write (aSSN, bISBN), PK: (aSSN, bISBN), FK: aSSN refs Author, bISBN refs Book.
Editor (SSN, first_name, last_name, address, salary, works_for, book_count), PK: SSN, FK: works_for refs Publisher.
Edit (eSSN, bISBN), PK: (eSSN, bISBN), FK: eSSN refs Editor, bISBN refs Book.
Author_Editor (aeSSN, hours), PK: aeSSN, FK: aeSSN refs Author, aeSSN refs Editor.

这是正确的方法吗？如果没有，我可以得到一个提示（任何提示表示赞赏）？

Select author.first_name, author.last_name
From author 
JOIN edit
ON author.ssn=edit.essn
Join write
Where edit.bisbn=write.bisbn and edit.isbn is not null;

提供每本书的标题，年份和出版商名称以及该书编辑的名字和姓氏。

SELECT title, year, published_by, first_name, last_name
FROM Book, 
Join Edit on ISBN=eSNN
Join Editor on SSN=eSSN

提供作者姓氏既不是“史密斯”也不是“Doe”的书籍的标题。

SELECT title

FROM book inner join write 
On book.isbn=write.bisbn
Join author on write.aSNN=Author.SNN
WHERE Author.last_name=’Doe’ and Author.first_name=’Smith’

Answer 1

你很亲密。编写连接时，需要指定表名和列名，并对每个连接执行相同的操作。所以第二个例子就是这样的：

提供每本书的标题，年份和出版商名称本书编辑的名字和姓氏。

SELECT book.title, 
       book.[year], 
       book.published_by, 
       editor.first_name, 
       editor.last_name 
FROM   book, 
       inner 
       JOIN edit 
         ON book.isbn = edit.bisbn 
       INNER JOIN editor 
               ON edit.essn = editor.ssn

Answer 2

虽然有一些ORM处理猜测要在更高级别加入的PK / FK，但在这个级别你通常需要明确指定你想要哪些列的数据＆＃39;匹配＆＃39;上

SELECT b.title, 
       b.year, 
       b.published_by, 
       ed.first_name, 
       ed.last_name 
FROM   book b, 
       inner 
       JOIN edit e 
         ON b.isbn = e.bisbn 
       JOIN editor ed
         ON e.essn = ed.ssn

希望这有帮助！

3个表及更多的SQL查询

2 个答案: