title: Using case expression in DATEADD interval
body: <p>Is possible to use case expression inside of DATEADD interval parameter?</p>
  
  <pre><code>select DATEADD(case c1 when 1 then HOUR when 2 then DAY end, c2, date) from T
  </code></pre>
  
  <p><strong>Update1</strong>: Sorry, I want to use it in where clause</p>
  
  <pre><code>select * from T where DATEADD(case c1 when 1 then HOUR when 2 then DAY end, c2, date) &lt; GETDATE()
  </code></pre>
  
  <p>Maybe there is another alternative.</p>
  
  <p>Thanks in advance,</p>