title: SQL query that summarizes each group
body: <p>I need help with this. I need to summarize each group of tests. The result should look like this:</p>
  <pre><code>name_of_the_group  |  all_test_cases  |  passed_test_cases  |  total_value
  numerical stability          4                    4                 80
  memory usage                 3                    2                 20
  corner cases                 0                    0                  0
  performance                  2                    0                  0
  </code></pre>
  <p>columns:</p>
  <ol>
  <li>name_of_the_group (all groups need to be displayed even if there are no corresponding tests)</li>
  <li>all_test_cases (number of tests in the group)</li>
  <li>passed_test_cases (number of test cases with the status OK)</li>
  <li>total_value (total value of passed tests in this group)</li>
  </ol>
  <p>Here is the fiddle example: <a href="http://sqlfiddle.com/#!17/e96109" rel="nofollow noreferrer">http://sqlfiddle.com/#!17/e96109</a></p>