module ActiveRecord::ConnectionHandling

Constants

DEFAULT_ENV
RAILS_ENV

Attributes

connection_specification_name[W]

Public Instance Methods

connected?() click to toggle source

Returns true if Active Record is connected.

# File lib/active_record/connection_handling.rb, line 132
def connected?
  connection_handler.connected?(connection_specification_name)
end
connection() click to toggle source

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.

# File lib/active_record/connection_handling.rb, line 90
def connection
  retrieve_connection
end
connection_config() click to toggle source

Returns the configuration of the associated connection as a hash:

ActiveRecord::Base.connection_config
# => {pool: 5, timeout: 5000, database: "db/development.sqlite3", adapter: "sqlite3"}

Please use only for reading.

# File lib/active_record/connection_handling.rb, line 119
def connection_config
  connection_pool.spec.config
end
connection_id() click to toggle source
# File lib/active_record/connection_handling.rb, line 105
def connection_id
  ActiveRecord::RuntimeRegistry.connection_id ||= Thread.current.object_id
end
connection_id=(connection_id) click to toggle source
# File lib/active_record/connection_handling.rb, line 109
def connection_id=(connection_id)
  ActiveRecord::RuntimeRegistry.connection_id = connection_id
end
connection_pool() click to toggle source
# File lib/active_record/connection_handling.rb, line 123
def connection_pool
  connection_handler.retrieve_connection_pool(connection_specification_name) or raise ConnectionNotEstablished
end
connection_specification_name() click to toggle source

Return the specification id from this class otherwise look it up in the parent.

# File lib/active_record/connection_handling.rb, line 98
def connection_specification_name
  if !defined?(@connection_specification_name) || @connection_specification_name.nil?
    return self == Base ? "primary" : superclass.connection_specification_name
  end
  @connection_specification_name
end
establish_connection(spec = nil) click to toggle source

Establishes the connection to the database. Accepts a hash as input where the :adapter 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:  "mysql2",
  host:     "localhost",
  username: "myuser",
  password: "mypass",
  database: "somedatabase"
)

Example for SQLite database:

ActiveRecord::Base.establish_connection(
  adapter:  "sqlite3",
  database: "path/to/dbfile"
)

Also accepts keys as strings (for parsing from YAML for example):

ActiveRecord::Base.establish_connection(
  "adapter"  => "sqlite3",
  "database" => "path/to/dbfile"
)

Or a URL:

ActiveRecord::Base.establish_connection(
  "postgres://myuser:mypass@localhost/somedatabase"
)

In case ActiveRecord::Base.configurations is set (Rails automatically loads the contents of config/database.yml into it), a symbol can also be given as argument, representing a key in the configuration hash:

ActiveRecord::Base.establish_connection(:production)

The exceptions AdapterNotSpecified, AdapterNotFound and ArgumentError may be returned on an error.

# File lib/active_record/connection_handling.rb, line 47
def establish_connection(spec = nil)
  raise RuntimeError, "Anonymous class is not allowed." unless name

  spec     ||= DEFAULT_ENV.call.to_sym
  resolver =   ConnectionAdapters::ConnectionSpecification::Resolver.new configurations
  # TODO: uses name on establish_connection, for backwards compatibility
  spec     =   resolver.spec(spec, self == Base ? "primary" : name)

  unless respond_to?(spec.adapter_method)
    raise AdapterNotFound, "database configuration specifies nonexistent #{spec.config[:adapter]} adapter"
  end

  remove_connection(spec.name)
  self.connection_specification_name = spec.name
  connection_handler.establish_connection spec
end
remove_connection(name = nil) click to toggle source
# File lib/active_record/connection_handling.rb, line 136
def remove_connection(name = nil)
  name ||= @connection_specification_name if defined?(@connection_specification_name)
  # if removing a connection that have a pool, we reset the
  # connection_specification_name so it will use the parent
  # pool.
  if connection_handler.retrieve_connection_pool(name)
    self.connection_specification_name = nil
  end

  connection_handler.remove_connection(name)
end
retrieve_connection() click to toggle source
# File lib/active_record/connection_handling.rb, line 127
def retrieve_connection
  connection_handler.retrieve_connection(connection_specification_name)
end