title: SUM for all columns in LINQ
body: <p>I have an SQL table with many columns(~200). </p>
  
  <p>I want to create a LINQ query to obtain the sum of all rows by column. The result to be one row which represents the SUM of each column. </p>
  
  <p><strong>How can be done this LINQ query?</strong> </p>
  
  <p>It's difficult to create a specific <code>.Sum(...)</code> for each column.</p>