title: SQL group by months, display empty months
body: <p>I got an sql fiddle for this with minimal data. My Database contains over 1000 output columns for my query which I couldnt load into sqlFiddle.</p>
  
  <p>I would like to display ALL months for all years found.
  In my example Car 1 was only sold in 2003 and I would like to display all empty months for 2003.</p>
  
  <p>For Car 2 it was sold in 2003 and 2004. So I would like to display all empty months for 03 and 04.</p>
  
  <p>I have read a lot of similar questions and I think a simple JOIN to a month table should do the trick. But I dont know how to do joins properly.
  Could anyone help me out on this one?</p>
  
  <p>SQL Fiddle here:
  <a href="http://sqlfiddle.com/#!9/14b2f5/3" rel="nofollow noreferrer">http://sqlfiddle.com/#!9/14b2f5/3</a></p>
  
  <p>Also my real query in my mysql workbench and its output look like <a href="https://i.imgur.com/zUnUHe7.png" rel="nofollow noreferrer">THIS</a>. You can see that Feb. 2003 is missing there.
  I would like to display "1952 Alpine Renault 1300" - "0" - "February 2003" instead of nothing like it is now.</p>