title: Find the Supplier number for those suppliers who supply every part
body: <p>I have the following tables:</p>
  
  <pre><code>Suppliers(Sno, Sname, Address)
  Parts(Pno, Pname, Colour)
  Catalogue(Sno, Pno, Price)
  </code></pre>
  
  <p>and I want to find the Sno of the suppliers who supply every part.</p>
  
  <p>So far, I've written this:</p>
  
  <pre><code>SELECT s.sname
  FROM suppliers s JOIN catalogue c
  USING s.sno
  </code></pre>
  
  <p>Now how do I write the part "suppliers that supply every part"?</p>
  
  <p>I was thinking about having the count(*) from parts = count(pno) for each supplier Sno. Could someone please give me a hint/write the first part of the equality?</p>
  
  <p>Thanks!</p>