Skip to content
Relational Algebra at your fingertips
Branch: master
Clone or download
Fetching latest commit…
Cannot retrieve the latest commit at this time.
Permalink
Type Name Latest commit message Commit time
Failed to load latest commit information.
alf-core @ 8319270
alf-doc @ 2726dad
alf-rack @ f2017e6
alf-repl @ 3d4e9c7
alf-rest @ ffdeb28
alf-sequel @ 918de59
alf-shell @ 783a122
alf-sql @ cbd0c82
fixtures
lib
spec
tasks
.gitignore
.gitmodules
.travis.yml
CHANGELOG.md
Gemfile
Gemfile.ci
LICENCE.md
Manifest.txt
README.md
Rakefile
alf.gemspec
alf.noespec

README.md

Alf

Relational Algebra at your fingertips

Build Status Dependency Status

Links

Overview

Alf is a modern query language, rooted in relational algebra, and implemented as a Ruby Domain Specific Language. It is distributed as a consolidated ruby gem:

gem install alf

You'll also need the usual adapter gems for connecting to SQL engines, such as pg for PostgreSQL or sqlite3 for SQlite. I've not tested Alf against MySQL and won't.

See the official documentation for getting started using Alf in Ruby and in Shell.

Detailed overview

The consolidated gem is assembled from the following components:

  • alf-core core classes of Alf, algebra, memory engine, Relation, compiler, and so on. This is actually Alf itself, I would say.
  • alf-sql extension of core's compiler to handle SQL compilation specifically, in an abstract way.
  • alf-sequel an adapter for connecting to SQL DBMSs using Sequel.
  • alf-shell implements the commandline tool that you can use without even knowing ruby.
  • alf-rack a few Rack middlewares for using Alf in ruby web applications.
  • alf-doc is the source of all the documentation found in man pages (shell) and on try-alf.org.
  • try-alf is the source code of try-alf.org itself.

Those components are distributed as separated ruby gems as well. A typical ruby configuration (Gemfile) for using Alf and connecting to SQL databases is either:

# consolidated gem, possibly with a lot of uneeded dependencies.
gem "alf", "~> 0.15.0"

or

# take only those gems that you need, here for a web app connecting to SQL
# databases.
gem "alf-core", "~> 0.15.0"   # you can even omit this one
gem "alf-sequel", "~> 0.15.0"
gem "alf-rack", "~> 0.15.0"

Contributing

As usual, on github, issues and pull requests, either on sub-projects (if you know where your issue/contribution fits) or on this one (if you don't).

Integration work on Alf requires having all components available. The scenario below might be a good way for getting started:

git clone git://github.com/alf-tool/alf.git
git submodule init
git submodule update
rake mod:test
rake test

Let me know if some tests fail in your environment. I'm not sure to know the idiomatic way to use github with submodules when clones are involved. If you do know, feel free to contribute your first pull request on this README ;-)

You can’t perform that action at this time.
You signed in with another tab or window. Reload to refresh your session. You signed out in another tab or window. Reload to refresh your session.