title: Case expression "missing keyword" error
body: <p>I've got the following table:</p>
  
  <pre><code>City     | Inhabitants | Magnitude
  ---------+-------------+--------
  Zuerich  |  100000     | city
  London   | 5000000     | city
  New York | 5000000     | city
  </code></pre>
  
  <p>I want a read out a select query that if there are 5000000 inhabitants it has to give out "big city" like this:</p>
  
  <pre><code>City     | Inhabitants | Magnitude
  ---------+-------------+---------
  Zuerich  |  100000     | city
  London   | 5000000     | bigcity
  New York | 5000000     | bigcity
  </code></pre>
  
  <p>I've tried it with this case statement but it didn't work</p>
  
  <pre><code>SELECT
      CASE magnitude
         WHEN inhabitants LIKE '%5000000%'
            THEN 'bigcity'
         ELSE NULL
      END AS magnitude
  </code></pre>
  
  <p>I always get a "missing keyword" error.</p>
  
  <p>How can I write this query correctly?</p>