title: How to Subtract Pageviews in Google Data Studio using a CASE statement?
body: <p>I want to subtract <code>Pageviews</code> of a particular page from <code>Pageviews</code> of a different page, but when I try using <code>COUNT</code> with <code>CASE</code>, I get <code>1</code>:</p>
  <pre><code>COUNT(CASE
      WHEN page = &quot;www.link1.com&quot; THEN 1 END)
  </code></pre>
  <p>This gives me a wrong <code>COUNT</code>:</p>
  <pre><code>COUNT(CASE
      WHEN page = &quot;www.link1.com&quot; THEN 1
      ELSE 0 END)
  </code></pre>
  <p>What I ultimately want to do is:</p>
  <pre><code>COUNT(CASE
      WHEN page=&quot;www.link1.com&quot; OR page = &quot;www.link2.com&quot; THEN 1
      ELSE 0 END) - COUNT(CASE
      WHEN page=&quot;www.link3.com&quot; THEN 1
      ELSE 0 END)
  </code></pre>
  <p>I want the <code>COUNT</code> of <code>Users</code> who have visited <code>link3</code> but <strong>NOT</strong> from <code>link1</code> and <code>link2</code>. These links are steps in a funnel. <code>link1</code> is the first step in the funnel but <code>link2</code> and <code>link3</code> have more <code>Pageviews</code>. I want to show how many users have come from sources other than the previous funnel step (i.e, <code>link1</code>).</p>