Question

OK, I am having difficulties with this query, What I want to do is join titles.pub_id to publishers.pub_id and then join publishers.pub_id onto employee.pub_id.

This is what I have came up with so far

In the titles table
title_id is the primary key
pub_id is a foreign key

In the publishers table
pub_id is the primary key
pub_name is a canidate key

in the employee table pub_id is a foreign key

SELECT titles.title_id
FROM titles
INNER JOIN titleauthor on titleauthor.title_id = titles.title_id
--INNER JOIN employee on employee.pub_id = publishers.pub_id
--INNER JOIN publishers on publishers.pub_id = titles.pub_id

The error that I get from this query is

Msg 4104, Level 16, State 1, Line 1
The multi-part identifier "publishers.pub_id" could not be bound.

Answer 1

Joins are left-associative, so an ON clause can only refer to tables that are joined earlier in the query, not to tables that are joined later. So you need to change the order of these two lines:

INNER JOIN employee on employee.pub_id = publishers.pub_id
INNER JOIN publishers on publishers.pub_id = titles.pub_id

giving this:

INNER JOIN publishers on publishers.pub_id = titles.pub_id
INNER JOIN employee on employee.pub_id = publishers.pub_id

in order that on employee.pub_id = publishers.pub_id not refer to publishers before it’s joined.