title: How to select words that has no definitions
body: <p>I have the following tables:</p>
  
  <p><strong>table: words</strong></p>
  
  <pre><code>    id word
      1  a
      2  b
      3  c ... so on
  </code></pre>
  
  <p><strong>table: definitions</strong></p>
  
  <pre><code> id wid land definition
   1  1   en   the first letter of the Roman alphabet
   2  1   en   the blood group "A"
   3  1   my   Definition of 'a' in Malaysia
   4  1   sg   Definition of 'a' in Singapore
   5  2   en   the second letter....
   6  2   en   the blood group "B"
   7  2   my   Definition of 'b' in Malaysia
   8  2   sg   Definition of 'b' in Singapore
   .... and so on.
  </code></pre>
  
  <p>My goal is to find a word that does not have a definition in a specific language, so I can add a definition. In this case, I want to pull up the word 'c'.</p>
  
  <p>So when I try:</p>
  
  <pre><code>"SELECT word FROM words, definition WHERE words.id = wid AND lang != 'my'
  </code></pre>
  
  <p>I get all words: 'a', 'b', and 'c'.</p>
  
  <p>How do I solve this problem?</p>