title: postgresql - query with not equal doesn't work
body: <p>this is dumb question but still, I'm trying to write a not equal where clause with postgresql the documentation show that the sign is <code>&lt;&gt;</code> or <code>!=</code> both always return 0 results
  the where is on an integer field. </p>
  
  <pre><code>select userid from users where usertype &lt;&gt; 2;
  select userid from users where usertype != 2;
  </code></pre>
  
  <p>the table looks like this:</p>
  
  <pre><code>CREATE TABLE Users(
      UserID BIGSERIAL PRIMARY KEY NOT NULL,
      Name VARCHAR (50) NOT NULL,
      PhoneNumber VARCHAR (20) UNIQUE NOT NULL,
      UserType INTEGER NULL
      );
  </code></pre>
  
  <p><strong>Note:</strong> the following workaround worka and return results</p>
  
  <pre><code>select userid from users where usertype &lt; 2 or usertype &gt; 2;
  </code></pre>
  
  <p>I was just wondering if anyone encounter the same problem?</p>