title: Sum of a column with distinct ID?
body: <p>i have a table that has multiple IDs and need a query to return the sum of a column for each ID. Calls_table looks like this</p>
  
  <pre><code>EmployeeID    TypeOfCall    InvoiceAmount 
  John          NC             50
  john          NC             100
  Joe           NC             76
  Joe           NC             50 
  </code></pre>
  
  <p>i have it so i have to do it employee by emplyee now like </p>
  
  <pre><code>SELECT sum(InvoiceAmount/2) as "Total Calls" 
  from Calls
  where TypeOfCall='NC' and EmployeeID='Derek';
  </code></pre>
  
  <p>but i would like it to be able to return all IDs in a list like this </p>
  
  <pre><code>Total Calls
  Joe              100
  John             68
  </code></pre>
  
  <p>I am sure i need to use the Distinct parameter but just cant figure out where</p>