MySQL combining outer joins - mysql

Question

For this question I have created a simple example that illustrates what I am asking.
Say I had a table called 'books'
+----+----------------------------+-----------+
| pk | title | author_id |
+----+----------------------------+-----------+
| 1 | The Lost Symbol | 1 |
| 2 | Follow Us Home | 2 |
| 3 | The Man in the High Castle | 3 |
+----+----------------------------+-----------+
(table a)
And another table called 'shops', that had a list of shops that sold each book:
+----+---------+-------------+-------+
| pk | book_id | shop_name | price |
+----+---------+-------------+-------+
| 1 | 1 | WHSmith | 5.00 |
| 2 | 1 | Waterstones | 7.00 |
| 3 | 1 | Amazon | 2.50 |
| 4 | 2 | WHSmith | 4.00 |
| 5 | 2 | Borders | 4.50 |
+----+---------+-------------+-------+
(table b)
If I do a simple select that grabs a book and all of the places it is sold using a join such as:
SELECT
books.*,
shops.shop_name,
shops.price
FROM
books
JOIN shops ON books.pk = shops.book_id
WHERE
book.book_name = "The Lost Symbol"
I would get results such as below:
+----+-----------------+-----------+-------------+-------+
| pk | title | author_id | shop_name | price |
+----+-----------------+-----------+-------------+-------+
| 1 | The Lost Symbol | 1 | WHSmith | 5.00 |
| 1 | The Lost Symbol | 1 | Waterstones | 7.00 |
| 1 | The Lost Symbol | 1 | Amazon | 2.50 |
+----+-----------------+-----------+-------------+-------+
(table c)
However, I would LIKE to receive results like this:
+----+-----------------+-----------+-------------+-------+
| pk | title | author_id | shop_name | price |
+----+-----------------+-----------+-------------+-------+
| 1 | The Lost Symbol | 1 | NULL | NULL |
| 1 | The Lost Symbol | 1 | WHSmith | 5.00 |
| 1 | The Lost Symbol | 1 | Waterstones | 7.00 |
| 1 | The Lost Symbol | 1 | Amazon | 2.50 |
+----+-----------------+-----------+-------------+-------+
(table d)
I.e. the first row is just the result of left outer join and the rest of the results are the the inner join.
An even more desired outcome is:
+------+-----------------+-----------+-------------+-------+
| pk | title | author_id | shop_name | price |
+------+-----------------+-----------+-------------+-------+
| 1 | The Lost Symbol | 1 | NULL | NULL |
| NULL | NULL | NULL | WHSmith | 5.00 |
| NULL | NULL | NULL | Waterstones | 7.00 |
| NULL | NULL | NULL | Amazon | 2.50 |
+------+-----------------+-----------+-------------+-------+
(table e)
Having shop_name and price concatenated and grouped in a single row seems not to work as it only does the first result from shops instead of all of them, also in my real world scenario, I have punctuation in the data so have to be careful with the separator.
So how would I get the result of table e?

Answer 1

You can use UNION ALL to build the required result set:
SELECT pk, title, author_id, NULL AS shop_name, NULL AS price
FROM books
WHERE books.title = "The Lost Symbol"
UNION ALL
SELECT NULL AS pk, NULL AS title, NULL AS author_id, shops.shop_name, shops.price
FROM books
JOIN shops ON books.pk = shops.book_id
WHERE books.title = "The Lost Symbol"
The first part of the union operation returns the first row of the result, i.e. the book title. The second part returns the rest of the rows, i.e.the shop names.
Demo here