title: SQL include AND exclude query
body: <p>I have table <em>t</em> that contains a person's name and the products they have:</p>
  
  <pre><code>NAME    PRODUCT
  Adam    a
  Adam    b
  Adam    c
  Ben     c
  Ben     d
  Chris   b
  Dave    a
  Dave    b
  Dave    c
  Dave    d
  Evan    a
  Evan    b
  Fred    a
  </code></pre>
  
  <p>And I want a SQL query that returns NAME when the person has Product a or b or both, AND does NOT have either product c nor d (nor e, f, ...):</p>
  
  <pre><code>NAME
  Chris
  Evan
  Fred
  </code></pre>
  
  <p>The actual 'does NOT have' list I'm working with is long, so I would like to avoid having to type in every single product name to exclude, if possible.</p>
  
  <p>Thanks in advance for your help.</p>