[sql] Add a summary row with totals

This is the more powerful grouping / rollup syntax you'll want to use in SQL Server 2008+. Always useful to specify the version you're using so we don't have to guess.

SELECT 
  [Type] = COALESCE([Type], 'Total'), 
  [Total Sales] = SUM([Total Sales])
FROM dbo.Before
GROUP BY GROUPING SETS(([Type]),());

Craig Freedman wrote a great blog post introducing GROUPING SETS.