module ActiveRecord::ConnectionHandling

Constants

DEFAULT_ENV
RAILS_ENV

Attributes

connection_specification_name[W]

Public Instance Methods

# File activerecord/lib/active_record/connection_handling.rb, line 122
def connected?
  connection_handler.connected?(connection_specification_name)
end

Returns true if Active Record is connected.

connection() Show source

# File activerecord/lib/active_record/connection_handling.rb, line 89
def connection
  retrieve_connection
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.

connection_config() Show source

# File activerecord/lib/active_record/connection_handling.rb, line 109
def connection_config
  connection_pool.spec.config
end

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.

connection_pool() Show source

# File activerecord/lib/active_record/connection_handling.rb, line 113
def connection_pool
  connection_handler.retrieve_connection_pool(connection_specification_name) || raise(ConnectionNotEstablished)
end

connection_specification_name() Show source

# File activerecord/lib/active_record/connection_handling.rb, line 96
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

Return the specification name from the current class or its parent.

establish_connection(config = nil) Show source

# File activerecord/lib/active_record/connection_handling.rb, line 49
def establish_connection(config = nil)
  raise "Anonymous class is not allowed." unless name

  config ||= DEFAULT_ENV.call.to_sym
  spec_name = self == Base ? "primary" : name
  self.connection_specification_name = spec_name

  resolver = ConnectionAdapters::ConnectionSpecification::Resolver.new(Base.configurations)
  spec = resolver.resolve(config).symbolize_keys
  spec[:name] = spec_name

  connection_handler.establish_connection(spec)
end

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.

remove_connection(name = nil) Show source

# File activerecord/lib/active_record/connection_handling.rb, line 126
def remove_connection(name = nil)
  name ||= @connection_specification_name if defined?(@connection_specification_name)
  # if removing a connection that has 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() Show source

# File activerecord/lib/active_record/connection_handling.rb, line 117
def retrieve_connection
  connection_handler.retrieve_connection(connection_specification_name)
end