title: Count distinct value pairs in multiple columns in SQL
body: <p>What query will count the number of rows, but distinct by three parameters?</p>
  
  <p>Example:</p>
  
  <pre><code>Id      Name        Address 
  ==============================
  1     MyName        MyAddress
  2     MySecondName  Address2
  </code></pre>
  
  <p>Something like:</p>
  
  <pre><code>select count(distinct id,name,address) from mytable
  </code></pre>