title: Sql short circuit OR or conditional exists in where clause
body: <p>I'm trying to force sql server to make a short circuit OR comparison on some fields. On the left side of the Or I have a simple variable comparison and on the right side I have a pretty 'heavy' subquery.</p>
  
  <pre><code>WHERE
  (@Var = 'DefaultValue' )  OR 
  Exists(select * from atable)
  </code></pre>
  
  <p>Is there any way to only execute the right side of the or statement if the first statement is false.</p>
  
  <p>I've tried case and if else statements but can't find any working syntax.</p>
  
  <p>I'm using a MS SQL server</p>