title: How to add a total row at the end of the table in t-sql?
body: <p>I need to add a row of sums as the last row of the table. For example:</p>
  
  <pre><code>   book_name   |   some_row1   |   some_row2   |   sum   
  ---------------+---------------+---------------+----------
      book1      |   some_data11 |   some_data12 |   100
      book2      |   some_data21 |   some_data22 |   300
      book3      |   some_data31 |   some_data32 |   500
   total_books=3 |   NULL        |   NULL        |   900
  </code></pre>
  
  <p>How can I do this? (T-SQL)</p>