Select as subquery

• Subquery at the same line with IN keyword

  SELECT SUM (Sales) FROM Store_Information
  WHERE Store_Name IN (SELECT Store_Name FROM Geography
                       WHERE Region_Name = 'West');

• Subquery in new line after IN keyword

  SELECT SUM (Sales) FROM Store_Information
  WHERE Store_Name IN 
         (SELECT Store_Name FROM Geography
          WHERE Region_Name = 'West');