DBF

DBF is a small fast library for reading dBase, xBase, Clipper and FoxPro database files

• Project page: http://github.com/infused/dbf
• API Documentation: http://rubydoc.info/github/infused/dbf/
• Report bugs: http://github.com/infused/dbf/issues
• Questions: Email mailto:keithm@infused.org and put DBF somewhere in the subject line
• Change log: https://github.com/infused/dbf/blob/master/CHANGELOG.md

NOTE: beginning with version 3 we have dropped support for Ruby 1.8 and 1.9. If you need support for older Rubies, please use 2.0.x (https://github.com/infused/dbf/tree/2_stable)

Compatibility

DBF is tested to work with the following versions of Ruby:

• MRI Ruby 2.0.x, 2.1.x, 2.2.x, 2.3.x
• JRuby head

Installation

Install the gem manually:

gem install dbf

Or add to your Gemfile:

gem 'dbf'

Basic Usage

Open a DBF file:

require 'dbf'
widgets = DBF::Table.new("widgets.dbf")

Enumerate all records

widgets.each do |record|
  puts record.name
  puts record.email
end

Find a single record

widget = widgets.find(6)

Note that find() will return nil if the requested record has been deleted and not yet pruned from the database.

The value for a attribute can be accessed via element reference in one of three ways

widget["SlotNumber"]   # original field name in dbf file
widget['slot_number']  # underscored field name string
widget[:slot_number]   # underscored field name symbol

Attributes can also be accessed as method using the underscored field name

widget.slot_number

Get a hash of all attributes. The keys are the original column names.

widget.attributes
# => {"Name" => "Thing1", "SlotNumber" => 1}

Search for records using a simple hash format. Multiple search criteria are ANDed. Use the block form if the resulting recordset could be large, otherwise all records will be loaded into memory.

# find all records with slot_number equal to s42
widgets.find(:all, slot_number: 's42') do |widget|
  # the record will be nil if deleted, but not yet pruned from the database
  if widget
    puts widget.serial_number
  end
end

# find the first record with slot_number equal to s42
widgets.find :first, slot_number: 's42'

# find record number 10
widgets.find(10)

Enumeration

DBF::Table is a Ruby Enumerable. This means you can use any Enumerable method. This means that you get a bunch of traversal, searching and sorting methods for free. For example, let's get only records created before January 1st, 2015:

widgets.select { |w| w.created_date < Date.new(2015, 1, 1) }

Or custom sorting:

widgets.sort_by { |w| w.created_date }

Encodings (Code Pages)

dBase supports encoding non-english characters in different formats. Unfortunately, the format used is not always set, so you may have to specify it manually. For example, you have a DBF file from Russia and you are getting bad data. Try using the 'Russion OEM' encoding:

table = DBF::Table.new('dbf/books.dbf', nil, 'cp866')

See doc/supported_encodings.csv for a full list of supported encodings.

Migrating to ActiveRecord

An example of migrating a DBF book table to ActiveRecord using a migration:

require 'dbf'

class Book < ActiveRecord::Base; end

class CreateBooks < ActiveRecord::Migration
  def self.up
    table = DBF::Table.new('db/dbf/books.dbf')
    eval(table.schema)

    Book.reset_column_information
    table.each do |record|
      Book.create(title: record.title, author: record.author)
    end
  end

  def self.down
    drop_table :books
  end
end

Migrating to Sequel

An example of migrating a DBF book table to Sequel using a migration:

require 'dbf'

class Book < Sequel::Model; end

Sequel.migration do
  up do
    table = DBF::Table.new('db/dbf/books.dbf')
    eval(table.schema(:sequel, true)) # passing true to limit output to create_table() only

    Book.reset_column_information
    table.each do |record|
      Book.create(title: record.title, author: record.author)
    end
  end

  down do
    drop_table(:books)
  end
end

Command-line utility

A small command-line utility called dbf is installed along with the gem.

$ dbf -h
usage: dbf [-h|-s|-a] filename
  -h = print this message
  -v = print the version number
  -s = print summary information
  -a = create an ActiveRecord::Schema
  -r = create a Sequel Migration
  -c = create a csv file

Create an executable ActiveRecord schema:

dbf -a books.dbf > books_schema.rb

Create an executable Sequel schema:

dbf -r books.dbf > migrate/001_create_books.rb

Dump all records to a CSV file:

dbf -c books.dbf > books.csv

Reading a Visual Foxpro database (v8, v9)

A special Database::Foxpro class is available to read Visual Foxpro container files (.dbc-files). When using this class, long field names are supported and tables can be referenced without using names.

require 'dbf'

contacts = DBF::Database::Foxpro.new('contactdatabase.dbc').contacts
my_contact = contacts.record(1).spouses_interests

dBase version compatibility

The basic dBase data types are generally supported well. Support for the advanced data types in dbase V and FoxPro are still experimental or not supported. If you have insight into how any of the unsupported data types are implemented, please give me a shout. FoxBase/dBase II files are not supported at this time.

See doc/supported_types.markdown for a full list of supported column types.

Limitations

• DBF is read-only
• Index files are not utilized

License

Copyright (c) 2006-2015 Keith Morrison <keithm@infused.org>

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.