+module ActiveRecord
+ class Base
+ class ConnectionSpecification #:nodoc:
+ attr_reader :config, :adapter_method
+ def initialize (config, adapter_method)
+ @config, @adapter_method = config, adapter_method
+ end
+ end
+
+ # The connection handler
+ cattr_accessor :connection_handler, :instance_writer => false
+ @@connection_handler = ConnectionAdapters::ConnectionHandler.new
+
+ # Returns the connection currently associated with the class. This can
+ # also be used to "borrow" the connection to do database work that isn't
+ # easily done without going straight to SQL.
+ def connection
+ self.class.connection
+ end
+
+ # Establishes the connection to the database. Accepts a hash as input where
+ # the <tt>:adapter</tt> key must be specified with the name of a database adapter (in lower-case)
+ # example for regular databases (MySQL, Postgresql, etc):
+ #
+ # ActiveRecord::Base.establish_connection(
+ # :adapter => "mysql",
+ # :host => "localhost",
+ # :username => "myuser",
+ # :password => "mypass",
+ # :database => "somedatabase"
+ # )
+ #
+ # Example for SQLite database:
+ #
+ # ActiveRecord::Base.establish_connection(
+ # :adapter => "sqlite",
+ # :database => "path/to/dbfile"
+ # )
+ #
+ # Also accepts keys as strings (for parsing from YAML for example):
+ #
+ # ActiveRecord::Base.establish_connection(
+ # "adapter" => "sqlite",
+ # "database" => "path/to/dbfile"
+ # )
+ #
+ # The exceptions AdapterNotSpecified, AdapterNotFound and ArgumentError
+ # may be returned on an error.
+ def self.establish_connection(spec = nil)
+ case spec
+ when nil
+ raise AdapterNotSpecified unless defined? RAILS_ENV
+ establish_connection(RAILS_ENV)
+ when ConnectionSpecification
+ @@connection_handler.establish_connection(name, spec)
+ when Symbol, String
+ if configuration = configurations[spec.to_s]
+ establish_connection(configuration)
+ else
+ raise AdapterNotSpecified, "#{spec} database is not configured"
+ end
+ else
+ spec = spec.symbolize_keys
+ unless spec.key?(:adapter) then raise AdapterNotSpecified, "database configuration does not specify adapter" end
+
+ begin
+ require 'rubygems'
+ gem "activerecord-#{spec[:adapter]}-adapter"
+ require "active_record/connection_adapters/#{spec[:adapter]}_adapter"
+ rescue LoadError
+ begin
+ require "active_record/connection_adapters/#{spec[:adapter]}_adapter"
+ rescue LoadError
+ raise "Please install the #{spec[:adapter]} adapter: `gem install activerecord-#{spec[:adapter]}-adapter` (#{$!})"
+ end
+ end
+
+ adapter_method = "#{spec[:adapter]}_connection"
+ if !respond_to?(adapter_method)
+ raise AdapterNotFound, "database configuration specifies nonexistent #{spec[:adapter]} adapter"
+ end
+
+ remove_connection
+ establish_connection(ConnectionSpecification.new(spec, adapter_method))
+ end
+ end
+
+ class << self
+ # Deprecated and no longer has any effect.
+ def allow_concurrency
+ ActiveSupport::Deprecation.warn("ActiveRecord::Base.allow_concurrency has been deprecated and no longer has any effect. Please remove all references to allow_concurrency.")
+ end
+
+ # Deprecated and no longer has any effect.
+ def allow_concurrency=(flag)
+ ActiveSupport::Deprecation.warn("ActiveRecord::Base.allow_concurrency= has been deprecated and no longer has any effect. Please remove all references to allow_concurrency=.")
+ end
+
+ # Deprecated and no longer has any effect.
+ def verification_timeout
+ ActiveSupport::Deprecation.warn("ActiveRecord::Base.verification_timeout has been deprecated and no longer has any effect. Please remove all references to verification_timeout.")
+ end
+
+ # Deprecated and no longer has any effect.
+ def verification_timeout=(flag)
+ ActiveSupport::Deprecation.warn("ActiveRecord::Base.verification_timeout= has been deprecated and no longer has any effect. Please remove all references to verification_timeout=.")
+ end
+
+ # Returns the connection currently associated with the class. This can
+ # also be used to "borrow" the connection to do database work unrelated
+ # to any of the specific Active Records.
+ def connection
+ retrieve_connection
+ end
+
+ def connection_pool
+ connection_handler.retrieve_connection_pool(self)
+ end
+
+ def retrieve_connection
+ connection_handler.retrieve_connection(self)
+ end
+
+ def connected?
+ connection_handler.connected?(self)
+ end
+
+ def remove_connection(klass = self)
+ connection_handler.remove_connection(klass)
+ end
+
+ delegate :clear_active_connections!, :clear_reloadable_connections!,
+ :clear_all_connections!,:verify_active_connections!, :to => :connection_handler
+ end
+ end
+end