This plugin was created by harukizaemon(github.com/harukizaemon) but is not supported currently by him. I’ve forked it to make it edge-rails compatible and to introduce new features.
RedHill on Rails Core provides bunch of useful database features:
-
Creating and dropping views;
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Creating and removing foreign-keys;
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Creating partial indexes (postgresql only)
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Obtaining indexes directly from a model class; and
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Determining when
Schema.define()
is running.
As a gem
gem install redhillonrails_core
…or as a plugin
script/plugin install http://github.com/mlomnicki/redhillonrails_core.git
The plugin provides a mechanism for creating and dropping views as well as preserving views when performing a schema dump:
create_view :normal_customers, "SELECT * FROM customers WHERE status = 'normal'" drop_view :normal_customers
The plugin provides two mechanisms for adding foreign keys as well as preserving foreign keys when performing a schema dump. (Using SQL-92 syntax and as such should be compatible with most databases that support foreign-key constraints.)
The first mechanism for creating foreign-keys allows you to add a foreign key when defining a table. For example:
create_table :orders do |t| ... t.foreign_key :customer_id, :customers, :id end
You also have the option of specifying what to do on delete/update using :on_delete
/:on_update
, respectively to one of: :cascade
; :restrict
; and :set_null
:
create_table :orders do |t| ... t.foreign_key :customer_id, :customers, :id, :on_delete => :set_null, :on_update => :cascade end
The second method allows you to create arbitrary foreign-keys at any time:
add_foreign_key(:orders, :customer_id, :customers, :id, :on_delete => :set_null, :on_update => :cascade)
In either case, if your database supports deferred foreign keys (for example PostgreSQL) you can specify this as well:
t.foreign_key :customer_id, :customers, :id, :deferrable => true add_foreign_key(:orders, :customer_id, :customers, :id, :deferrable => true)
By default, the foreign key will be assigned a name by the underlying database. However, if this doesn’t suit your needs, you can override the default assignment using the :name
option:
add_foreign_key(:orders, :customer_id, :customers, :id, :on_delete => :set_null, :on_update => :cascade, <strong>:name => :orders_customer_id_foreign_key<strong>)
You can also query the foreign keys for a model yourself by calling foreign_keys()
:
Order.foreign_keys
Or for an arbitrary table by calling foreign_keys(table_name)
on a database adapter.
Either method returns an array of the following meta-data:
-
name
- The name of the foreign key constraint; -
table_name
- The table for which the foreign-key was generated; -
column_names
- The column names in the table; -
references_table_name
- The table referenced by the foreign-key; and -
references_column_names
- The columns names in the referenced table.
If you need to drop a foreign-key, use:
remove_foreign_key :orders, :orders_ordered_by_id_fkey
The plugin also ensures that all foreign keys are output when performing a schema dump. This happens automatically when running rake migrate
or rake db:schema:dump
. This has particular implications when running unit tests that contain fixtures. To ensure the test data is correctly reset after each test, you should list your fixtures in order of parent->child. For example:
fixtures :customers, :products, :orders, :order_lines
Rails will then set-up and tear-down the fixtures in the correct sequence.
Some databases (PostgreSQL and MySQL for example) allow you to set a comment for a table. You can do this for existing tables by using:
set_table_comment :orders, "All pending and processed orders"
or even at the time of creation:
create_table :orders, :comment => "All pending and processed orders" do |t| ... end
You can clear table comments using:
clear_table_comment :orders
There is also a rake tasks to show all database tables and their comments:
rake db:comments
The plugin fully supports and understands the following active-record configuration properties:
-
config.active_record.pluralize_table_names
-
config.active_record.table_name_prefix
-
config.active_record.table_name_suffix
ActiveRecord::Base already provides a method on connection for obtaining the indexes for a given table. This plugin now makes it possible to obtain the indexes for a given model–ActiveRecord::Base
–class. For example:
Invoice.indexes
Would return all the indexes for the invoices
table.
Partial indexes index only a portion of the database. Only PostgreSQL supports this feature.
add_index :users, :username, :unique => true, :conditions => {:state => "active"}
Create expression-based indexes:
add_index :users, [:first_name, :last_name], :expression => 'LOWER(first_name || last_name)' add_index :places, :expression => '(sin(lat) * cos(lng))', :name => 'index_places_on_something' add_index :documents, :body, :expression => "USING gin (to_tsvector('english', body))"
Expression is a pass-through: no quoting, escaping is done on it. Presumably, this expression is part of migrations, or at least, code under your control.
For PostgreSQL, you can add an option :case_sensitive => false
to add_index
which will generate an expression index of the form:
LOWER(column_name)
This means finder queries of the form:
WHERE LOWER(column_name) = LOWER(?)
are able to use the indexes rather require, in the worst case, full-table scans.
Note also that this ties in well with Rails built-in support for case-insensitive searching:
validates_uniqueness_of :name, :case_sensitive => false
The plugin also adds a method–defining?()
–to ActiveRecord::Schema
to indicate when define()
is running. This is necessary as some migration plugins must change their behaviour accordingly.
redhillonrails_core uses Micronaut for specing. The examples are split per-database adapter. Run using Bundler:
$ bundle install $ bundle exec rake postgresql:examples
Running examples only will fail since the environment won’t be setup properly.
-
François Beausoleil - github.com/francois
-
Greg Barnett