Ben Cowley
Ben Cowley

Reputation: 39

Mysql Joining data from 3 tables

I can't seem to figure out what join I need to do. I have 3 tables which have all the information. I've map out the steps but I'm unsure what to do now, I need to display all the books listed from a specific author.

There is 3 tables I need to use

Here's the code so far, really I know I should use author name but i can't figure it out.

SELECT BOOK_CODE
FROM WROTE 
WHERE AUTHOR_NUM = 20
LEFT JOIN AUTHOR
ON WROTE.AUTHOR_NUM = AUTHOR.AUTHOR_NUM;

Upvotes: 0

Views: 35

Answers (2)

user7283402
user7283402

Reputation: 1

SELECT Book.book_code
FROM Book
LEFT JOIN WROTE ON WROTE.book_code = Book.book_code
LEFT JOIN AUTHOR ON AUTHOR.author_code = WROTE.author_number
WHERE AUTHOR.author_code IN (123,456)

Upvotes: 0

Deep Hakani
Deep Hakani

Reputation: 198

You need list of book, so start with book table then join it with wrote to get specific author and then join to author to get author data

SELECT BOOK_CODE
FROM BOOK
INNER JOIN  WROTE 
   ON WROTE.BOOK_CODE = BOOK.BOOK_CODE 
   AND WROTE.AUTHOR_NUM = 20
INNER JOIN AUTHOR
   ON AUTHOR.AUTHOR_NUM  = WROTE.AUTHOR_NUM 

Upvotes: 2

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