title: Default values for COUNT in MySQL
body: <p>I have a table looking something like this:</p>
  
  <pre><code>+-------+-----+
  |country|prop1|
  +-------+-----+
  |RO     |  1  |
  |RO     |  2  |
  |UK     |  1  |
  |IT     |  2  |
  +-------+-----+
  </code></pre>
  
  <p>I want to count the rows for which the prop1 is not null and I use the following select:</p>
  
  <pre><code>SELECT `country`, COUNT(*) as number FROM table GROUP BY `country`;
  </code></pre>
  
  <p>this will return:</p>
  
  <pre><code>+-------+------+
  |country|number|
  +-------+------+
  |RO     |  2   |
  |UK     |  1   |
  |IT     |  1   |
  +-------+------+
  </code></pre>
  
  <p>however I need the following:</p>
  
  <pre><code>+-------+------+
  |country|number|
  +-------+------+
  |RO     |  2   |
  |UK     |  1   |
  |IT     |  1   |
  |FR     |  0   |
  +-------+------+
  </code></pre>
  
  <p>Do you think something like this can be possible to write directly in SQL? I was thinking something like specifying list of possible values for "country" and a default value (0) if it is not found in the table.</p>