X-Git-Url: https://git.openstreetmap.org/rails.git/blobdiff_plain/3a0f4d30cf6cbe921ffa2a78e5a0192c32a86ef4..62f999cd835dad3c16ea46e340bc15b0e43f31db:/vendor/gems/composite_primary_keys-1.1.0/website/index.html diff --git a/vendor/gems/composite_primary_keys-1.1.0/website/index.html b/vendor/gems/composite_primary_keys-1.1.0/website/index.html deleted file mode 100644 index 27baec185..000000000 --- a/vendor/gems/composite_primary_keys-1.1.0/website/index.html +++ /dev/null @@ -1,199 +0,0 @@ - - - - - - - Composite Primary Keys - - - - - - -
- -

Composite Primary Keys

-
- Get Version - 1.1.0 -
-

→ Ruby on Rails

-

→ ActiveRecords

-

What

-

Ruby on Rails does not support composite primary keys. This free software is an extension
-to the database layer of Rails – ActiveRecords – to support composite primary keys as transparently as possible.

-

Any Ruby script using ActiveRecords can use Composite Primary Keys with this library.

-

Installing

-

sudo gem install composite_primary_keys

-

Rails: Add the following to the bottom of your environment.rb file

-

require 'composite_primary_keys'

-

Ruby scripts: Add the following to the top of your script

-

require 'rubygems'
-require 'composite_primary_keys'

-

The basics

-

A model with composite primary keys would look like…

-

class Membership < ActiveRecord::Base
-  # set_primary_keys *keys - turns on composite key functionality
-  set_primary_keys :user_id, :group_id
-  belongs_to :user
-  belongs_to :group
-  has_many :statuses, :class_name => 'MembershipStatus', :foreign_key => [:user_id, :group_id]
-end

-

A model associated with a composite key model would be defined like…

-

class MembershipStatus < ActiveRecord::Base
-  belongs_to :membership, :foreign_key => [:user_id, :group_id]
-end

-

That is, associations can include composite keys too. Nice.

-

Demonstration of usage

-

Once you’ve created your models to specify composite primary keys (such as the Membership class) and associations (such as MembershipStatus#membership), you can uses them like any normal model with associations.

-

But first, lets check out our primary keys.

-

MembershipStatus.primary_key # => "id"    # normal single key
-Membership.primary_key  # => [:user_id, :group_id] # composite keys
-Membership.primary_key.to_s # => "user_id,group_id"

-

Now we want to be able to find instances using the same syntax we always use for ActiveRecords…

-

MembershipStatus.find(1)    # single id returns single instance
-=> <MembershipStatus:0x392a8c8 @attributes={"id"=>"1", "status"=>"Active"}>
-Membership.find(1,1)  # composite ids returns single instance
-=> <Membership:0x39218b0 @attributes={"user_id"=>"1", "group_id"=>"1"}>

-

Using Ruby on Rails? You’ll want to your url_for helpers
-to convert composite keys into strings and back again…

-

Membership.find(:first).to_param # => "1,1"

-

And then use the string id within your controller to find the object again

-

params[:id] # => '1,1'
-Membership.find(params[:id])
-=> <Membership:0x3904288 @attributes={"user_id"=>"1", "group_id"=>"1"}>

-

That is, an ActiveRecord supporting composite keys behaves transparently
-throughout your application. Just like a normal ActiveRecord.

-

Other tricks

-

Pass a list of composite ids to the #find method

-

Membership.find [1,1], [2,1]
-=> [
-  <Membership:0x394ade8 @attributes={"user_id"=>"1", "group_id"=>"1"}>, 
-  <Membership:0x394ada0 @attributes={"user_id"=>"2", "group_id"=>"1"}>
-]

-

Perform #count operations

-

MembershipStatus.find(:first).memberships.count # => 1

-

Routes with Rails

-

From Pete Sumskas:

-
-

I ran into one problem that I didn’t see mentioned on this list –
- and I didn’t see any information about what I should do to address it in the
- documentation (might have missed it).

-

The problem was that the urls being generated for a ‘show’ action (for
- example) had a syntax like:
-
- 

/controller/show/123000,Bu70

-

for a two-field composite PK. The default routing would not match that,
- so after working out how to do the routing I added:
-
- 

map.connect ':controller/:action/:id', :id => /\w+(,\w+)*/

-
- to my route.rb file.

-
-

-

Which databases?

-

A suite of unit tests have been run on the following databases supported by ActiveRecord:

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
DatabaseTest SuccessUser feedback
mysql YESYES (Yes! or No…)
sqlite3 YESYES (Yes! or No…)
postgresqlYESYES (Yes! or No…)
oracle YESYES (Yes! or No…)
sqlserver ??? (I can help)??? (Yes! or No…)
db2 ??? (I can help)??? (Yes! or No…)
firebird ??? (I can help)??? (Yes! or No…)
sybase ??? (I can help)??? (Yes! or No…)
openbase ??? (I can help)??? (Yes! or No…)
frontbase ??? (I can help)??? (Yes! or No…)
-

Dr Nic’s Blog

-

http://www.drnicwilliams.com – for future announcements and
-other stories and things.

-

Forum

-

http://groups.google.com/group/compositekeys

-

How to submit patches

-

Read the 8 steps for fixing other people’s code and for section 8b: Submit patch to Google Groups, use the Google Group above.

-

The source for this project is available via git. You can browse and/or fork the source, or to clone the project locally:
-
-

git clone git://github.com/drnic/composite_primary_keys.git

-

Licence

-

This code is free to use under the terms of the MIT licence.

-

Contact

-

Comments are welcome. Send an email to Dr Nic Williams.

-

- Dr Nic, 25th October 2008
- Theme extended from Paul Battley -

-
- - - - - -