Select rows with dates and article points (without relation)

Question

Iv got following tables:

articles

+----+-------------+-----------------------------+--------------+
| ID | ID_group_AG | Title                       | Date_publish |
+----+-------------+-----------------------------+--------------+
|  1 |          10 | O obrotach sfer niebieskich | 2009-05-07   |
|  2 |          11 | Technologia betonu          | 2011-03-21   |
|  3 |          12 | test                        | 2008-01-13   |
+----+-------------+-----------------------------+--------------+

employee

+----+-----------+-----------+
| ID | Name      | Surname   |
+----+-----------+-----------+
|  1 | Andrzej   | Gacek     |
|  2 | Leszek    | Ksiazek   |
|  3 | Krzysztof | Skibinski |
|  4 | Andrzej   | Inny      |
+----+-----------+-----------+

articlesGroup

+----+----------+---------------+----------------+
| ID | ID_group | ID_employee   | Points         |
+----+----------+---------------+----------------+
|  1 |       10 |             1 |              3 |
|  2 |       10 |             3 |              3 |
|  3 |       11 |             1 |              2 |
|  4 |       11 |             2 |              2 |
|  5 |       11 |             4 |              2 |
|  6 |       12 |             4 |              6 |
+----+----------+---------------+----------------+

And following relations:

articles.ID_group_AG => articlesGroup.ID_group

articlesGroup.ID_employee => employee.ID

---

What I need to do is to print all article points related to a employee, article and publish date, so I use folowing query:

SELECT
  p.Name,
  p.Surname,
  a.Date_publish,
  ag.Points
FROM
  employee p,
  articles a,
  articlesGroup ag
WHERE
  (ag.ID_group = a.ID_group_AG) AND
  (ag.ID_employee = p.ID)

and I get:

+-----------+-----------+--------------+----------------+
| Name      | Surname   | Date_publish | Points         |
+-----------+-----------+--------------+----------------+
| Andrzej   | Gacek     | 2009-05-07   |              3 |
| Andrzej   | Gacek     | 2011-03-21   |              2 |
| Leszek    | Ksiazek   | 2011-03-21   |              2 |
| Krzysztof | Skibinski | 2009-05-07   |              3 |
| Andrzej   | Inny      | 2011-03-21   |              2 |
| Andrzej   | Inny      | 2008-01-13   |              6 |
+-----------+-----------+--------------+----------------+

---

Now lets get to the problem :)

Im using pChart library to make charts.

I want to put on Y axis Points, on X axis all Dates regarding each employee.

So Points array for employee "Andrzej Gacek" will be: [3,2]

for employee "Krzysztof Skibinski" will be: [3]

and Date array (sorted): ["2008-01-13","2009-05-07","2011-03-21"]

I need to add zero points to employee Points array for ex. for "Andrzej Gacek" array should look like: [0,3,2] so Point will correlate with Dates.

How to form a query to add zeroes to points so the output of the query would look like this:

+-----------+-----------+--------------+----------------+
| Name      | Surname   | Date_publish | Points         |
+-----------+-----------+--------------+----------------+
| Andrzej   | Gacek     | 2009-05-07   |              3 |
| Andrzej   | Gacek     | 2011-03-21   |              2 |
| Andrzej   | Gacek     | 2008-01-13   |              0 |
| Leszek    | Ksiazek   | 2011-03-21   |              2 |
| Leszek    | Ksiazek   | 2009-05-07   |              0 |
| Leszek    | Ksiazek   | 2008-01-13   |              0 |
| Krzysztof | Skibinski | 2009-05-07   |              3 |
| Krzysztof | Skibinski | 2011-03-21   |              0 |
| Krzysztof | Skibinski | 2008-01-13   |              0 |
| Andrzej   | Inny      | 2011-03-21   |              2 |
| Andrzej   | Inny      | 2008-01-13   |              6 |
| Andrzej   | Inny      | 2009-05-07   |              0 |
+-----------+-----------+--------------+----------------+

Answer 1

You have to create a Cartesian Product to get the results you are looking for. I've used a CROSS JOIN to get the dates for each employee.

Give this a try:

SELECT DISTINCT E.Name,
  E.SurName,
  a.Date_Publish, 
  IFNULL(AG.Points,0) Points
FROM Articles A CROSS JOIN
  Employee E LEFT JOIN
  ArticlesGroup AG ON ag.ID_group = a.ID_group_AG 
    AND E.Id = ag.ID_employee

And here is the SQL Fiddle.