title: Oracle SQL checking field is not a value
body: <p>I am using Oracle SQL and am trying to build out sql that meets the following condition:
  If PS_EMPLOYEES.COUNTRY&lt;>USA, enter PS_EMPLOYEES.POSTAL, else, leave blank</p>
  
  <p>The below code does this EXCEPT it checks if the country is equal to USA.  How would I do the opposite?</p>
  
  <pre><code>, ZIPCODE = 
      (SELECT decode(t2.COUNTRY, 'USA', t2.POSTAL, ' ') zipcode
      FROM PS_EMPLOYEES t2
  ...
  </code></pre>