Example SQL Report with the Ruby Spreadsheet Gem

By kenglish

If you want to create a Excel reports for your users, this can be done rather easily in Ruby using the Spreadsheet Gem.

def spreadsheet_report(excel_filename, worksheet_name, 
                       column_order, result)
    book = Spreadsheet::Workbook.new
    sheet1 = book.create_worksheet :name => worksheet_name
 
    rownum = 0
    for column in column_order
      sheet1.row(rownum).push column
    end
    for row in result
      rownum += 1
      for column in column_order
        sheet1.row(rownum).push row[column].nil? ? 'N/A' : row[column]
      end
    end
    book.write "#{excel_filename}.xls"
 
end

Here’s what the code would like in your rake task

column_order = ["Name", "DOB", "Rank","Hire Date", 
                "Height", "Weight" ]
 
sql =<<-END
  SELECT name AS Name,
   date_of_birth AS DOB, 
   rank AS Rank,
   hire_date Hire Date,
   height AS Height,
   weight AS  Weight
  FROM fire_fighters
  ORDER BY name
END
 
conn  = ActiveRecord::Base.connection
result    = conn.select_all(sql)
 
excel_filename = "FireFighterReport#{Time.year}" 
worksheet_name = "FireFighter Report #{Time.year}"
spreadsheet_report(excel_filename, worksheet_name, 
                   column_order, result)