title: SQL - don't display row when two criteria are met
body: <p>At first I thought I could accomplish this in the <code>WHERE</code> clause of my query and using a <code>CASE</code> (see below) but I'm having some trouble getting the result I need. This query is to get product info for clients in a database. I need to not return rows at all if a certain product is ordered by a certain client. The problem is if I remove the product, then any other client with that product will show up as any client can order this product. I'm stumped on how to accomplish this.</p>
  
  <pre><code>Select
     OrderNumber, Client, Product From Orders
  WHERE
    Product not in(CASE WHEN client = 'client_a' and product = 'product_1' THEN Product   END)
  </code></pre>
  
  <p>Hoping to see something like this as a result, the point being to show product_1 for all clients except client_a:</p>
  
  <pre><code>ordernumber client          product
  123         client a    product 2
  456         client b    product 1
  789         client b    product 2
  </code></pre>