title: Why does NULL = NULL evaluate to false in SQL server
body: <p>In SQL server if you have  <code>nullParam=NULL</code> in a where clause, it always evaluates to false. This is counterintuitive and has caused me many errors. I do understand the <code>IS NULL</code> and <code>IS NOT NULL</code> keywords are the correct way to do it. But why does SQL server behave this way?</p>