How to get data by using different column values refrencing same table

Question

I have two tables:

create table 
books (
       id int
      ,bookname text
      );

---

create table 
users(
      id int
     ,name text
     ,book_1 int
     ,book_2 int
     ,book_3 int
     );

Now, 'book_1', 'book_2', 'book_3' contains id of table 'books'.

I am trying to create a single query using join to get the all three book names with user name.

I am able to get one book name, but how will I get all the three books name?

SELECT user.name
      ,books.name 
FROM user LEFT JOIN books ON books.id=user.book_1; 

(This is giving me one book detail)

Using PostgreSQL.

I want result in one row. like

username, book_1_name, book_2_name, book_3_name 

Don't want multiple rows.

Answer 1

You can use sub-selects to get bookname of each username in a single row ( if id in table books is unique )

select name username
      ,(select bookname from books where id=book_1) book1_name
      ,(select bookname from books where id=book_2) book2_name
      ,(select bookname from books where id=book_3) book3_name
from users

> SQLFIDDLE DEMO

Answer 2

SELECT user.name
      ,books.name
FROM user LEFT JOIN books ON books.id=user.book_1
          OR books.id=user.book_2 
          OR books.id=user.book_3; 

join on all id's

Answer 3

This may help you

SELECT user.name
      ,books.name 
FROM user LEFT JOIN books ON books.id in (select id from  books)

---