title: Why is there is a difference between equality comparison between equal operator and like operator?
body: <pre><code>SELECT au_lname, au_fname  
  FROM authors
  WHERE au_lname = 'Green '
  </code></pre>
  
  <pre>
  au_lname                                 au_fname
  ---------------------------------------- --------------------
  Green                                    Marjorie
  </pre>
  
  <pre><code>SELECT au_lname, au_fname
  FROM authors
  WHERE au_lname LIKE 'Green '
  </code></pre>
  
  <pre>
  au_lname                                 au_fname
  ---------------------------------------- --------------------
  </pre>
  
  <p>Could anyone please explain me why is the second query is not returning the expected row?</p>