How do I query a MS Access database table, and export the information to Excel using Ruby and win32ole?

Question

I'm new to Ruby, and I'm trying to query an existing MS Access database for information for a report. I want this information stored in an Excel file. How would I do this?

Answer 1

Why do you want to do this? You can simply query your db from Excel directly. Check out this tutorial.

Answer 2

Try one of these:

OLE:

require 'win32ole'

class AccessDbExample
  @ado_db = nil

  # Setup the DB connections
  def initialize filename
    @ado_db             = WIN32OLE.new('ADODB.Connection')
    @ado_db['Provider'] = "Microsoft.Jet.OLEDB.4.0"
    @ado_db.Open(filename)
  rescue Exception => e
    puts "ADO failed to connect"
    puts e
  end

  def table_to_csv table
    sql = "SELECT * FROM #{table};"

    results = WIN32OLE.new('ADODB.Recordset')
    results.Open(sql, @ado_db)

    File.open("#{table}.csv", 'w') do |file|
      fields = []
      results.Fields.each{|f| fields << f.Name}
      file.puts fields.join(',')

      results.GetRows.transpose.each do |row|
        file.puts row.join(',')
      end
    end unless results.EOF

    self
  end

  def cleanup
    @ado_db.Close unless @ado_db.nil?
  end
end

AccessDbExample.new('test.mdb').table_to_csv('colors').cleanup

ODBC:

  require 'odbc'

    include ODBC

    class AccessDbExample
      @obdc_db = nil

      # Setup the DB connections
      def initialize filename
        drv                 = Driver.new
        drv.name            = 'AccessOdbcDriver'
        drv.attrs['driver'] = 'Microsoft Access Driver (*.mdb)'
        drv.attrs['dbq']    = filename
        @odbc_db            = Database.new.drvconnect(drv) 
      rescue 
          puts "ODBC failed to connect"
      end

      def table_to_csv table
        sql = "SELECT * FROM #{table};"

        result = @odbc_db.run(sql)
        return nil if result == -1

        File.open("#{table}.csv", 'w') do |file|
          header_row = result.columns(true).map{|c| c.name}.join(',')
          file.puts header_row

          result.fetch_all.each do |row|
            file.puts row.join(',')
          end
        end

        self
      end

      def cleanup
        @odbc_db.disconnect unless @odbc_db.nil?
      end
    end

    AccessDbExample.new('test.mdb').table_to_csv('colors').cleanup

Answer 3

As Johannes said, you can query the database from Excel.

If, however, you would prefer to work with Ruby...

You can find info on querying Access/Jet databases with Ruby here.

Lots of info on automating Excel with Ruby can be found here.

David