Module: ActiveRecord::ConnectionHandling

Included in:
Base
Defined in:
activerecord/lib/active_record/connection_adapters/mysql_adapter.rb,
activerecord/lib/active_record/connection_handling.rb,
activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb,
activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb,
activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb

Overview

:nodoc:

Defined Under Namespace

Classes: MergeAndResolveDefaultUrlConfig

Constant Summary collapse

RAILS_ENV = 
-> { Rails.env if defined?(Rails) }
DEFAULT_ENV = 
-> { RAILS_ENV.call || "default_env" }
VALID_CONN_PARAMS = 
[:host, :hostaddr, :port, :dbname, :user, :password, :connect_timeout,
:client_encoding, :options, :application_name, :fallback_application_name,
:keepalives, :keepalives_idle, :keepalives_interval, :keepalives_count,
:tty, :sslmode, :requiressl, :sslcompression, :sslcert, :sslkey,
:sslrootcert, :sslcrl, :requirepeer, :krbsrvname, :gsslib, :service]

Instance Method Summary collapse

Instance Method Details

#clear_cache! ⇒ Object

:nodoc:



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# File 'activerecord/lib/active_record/connection_handling.rb', line 125

def clear_cache! # :nodoc:
  connection.schema_cache.clear!
end

#connected? ⇒ Boolean

Returns true if Active Record is connected.

Returns:

  • (Boolean) 


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# File 'activerecord/lib/active_record/connection_handling.rb', line 117

def connected?
  connection_handler.connected?(self)
end

#connection ⇒ Object

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.



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# File 'activerecord/lib/active_record/connection_handling.rb', line 86

def connection
  retrieve_connection
end

#connection_config ⇒ Object

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.



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# File 'activerecord/lib/active_record/connection_handling.rb', line 104

def connection_config
  connection_pool.spec.config
end

#connection_id ⇒ Object 



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# File 'activerecord/lib/active_record/connection_handling.rb', line 90

def connection_id
  ActiveRecord::RuntimeRegistry.connection_id
end

#connection_id=(connection_id) ⇒ Object 



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# File 'activerecord/lib/active_record/connection_handling.rb', line 94

def connection_id=(connection_id)
  ActiveRecord::RuntimeRegistry.connection_id = connection_id
end

#connection_pool ⇒ Object 



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# File 'activerecord/lib/active_record/connection_handling.rb', line 108

def connection_pool
  connection_handler.retrieve_connection_pool(self) or raise ConnectionNotEstablished
end

#establish_connection(spec = nil) ⇒ Object

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:  "mysql",
  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.



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# File 'activerecord/lib/active_record/connection_handling.rb', line 47

def establish_connection(spec = nil)
  spec     ||= DEFAULT_ENV.call.to_sym
  resolver =   ConnectionAdapters::ConnectionSpecification::Resolver.new configurations
  spec     =   resolver.spec(spec)

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

  remove_connection
  connection_handler.establish_connection self, spec
end

#mysql2_connection(config) ⇒ Object

Establishes a connection to the database that’s used by all Active Record objects.



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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 9

def mysql2_connection(config)
  config = config.symbolize_keys

  config[:username] = 'root' if config[:username].nil?

  if Mysql2::Client.const_defined? :FOUND_ROWS
    config[:flags] = Mysql2::Client::FOUND_ROWS
  end

  client = Mysql2::Client.new(config)
  options = [config[:host], config[:username], config[:password], config[:database], config[:port], config[:socket], 0]
  ConnectionAdapters::Mysql2Adapter.new(client, logger, options, config)
rescue Mysql2::Error => error
  if error.message.include?("Unknown database")
    raise ActiveRecord::NoDatabaseError.new(error.message)
  else
    raise error
  end
end

#mysql_connection(config) ⇒ Object

Establishes a connection to the database that’s used by all Active Record objects.



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# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 21

def mysql_connection(config)
  config = config.symbolize_keys
  host     = config[:host]
  port     = config[:port]
  socket   = config[:socket]
  username = config[:username] ? config[:username].to_s : 'root'
  password = config[:password].to_s
  database = config[:database]

  mysql = Mysql.init
  mysql.ssl_set(config[:sslkey], config[:sslcert], config[:sslca], config[:sslcapath], config[:sslcipher]) if config[:sslca] || config[:sslkey]

  default_flags = Mysql.const_defined?(:CLIENT_MULTI_RESULTS) ? Mysql::CLIENT_MULTI_RESULTS : 0
  default_flags |= Mysql::CLIENT_FOUND_ROWS if Mysql.const_defined?(:CLIENT_FOUND_ROWS)
  options = [host, username, password, database, port, socket, default_flags]
  ConnectionAdapters::MysqlAdapter.new(mysql, logger, options, config)
rescue Mysql::Error => error
  if error.message.include?("Unknown database")
    raise ActiveRecord::NoDatabaseError.new(error.message)
  else
    raise error
  end
end

#postgresql_connection(config) ⇒ Object

Establishes a connection to the database that’s used by all Active Record objects



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# File 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb', line 27

def postgresql_connection(config)
  conn_params = config.symbolize_keys

  conn_params.delete_if { |_, v| v.nil? }

  # Map ActiveRecords param names to PGs.
  conn_params[:user] = conn_params.delete(:username) if conn_params[:username]
  conn_params[:dbname] = conn_params.delete(:database) if conn_params[:database]

  # Forward only valid config params to PGconn.connect.
  conn_params.keep_if { |k, _| VALID_CONN_PARAMS.include?(k) }

  # The postgres drivers don't allow the creation of an unconnected PGconn object,
  # so just pass a nil connection object for the time being.
  ConnectionAdapters::PostgreSQLAdapter.new(nil, logger, conn_params, config)
end

#remove_connection(klass = self) ⇒ Object 



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# File 'activerecord/lib/active_record/connection_handling.rb', line 121

def remove_connection(klass = self)
  connection_handler.remove_connection(klass)
end

#retrieve_connection ⇒ Object 



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# File 'activerecord/lib/active_record/connection_handling.rb', line 112

def retrieve_connection
  connection_handler.retrieve_connection(self)
end

#sqlite3_connection(config) ⇒ Object

sqlite3 adapter reuses sqlite_connection.



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# File 'activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb', line 11

def sqlite3_connection(config)
  # Require database.
  unless config[:database]
    raise ArgumentError, "No database file specified. Missing argument: database"
  end

  # Allow database path relative to Rails.root, but only if
  # the database path is not the special path that tells
  # Sqlite to build a database only in memory.
  if ':memory:' != config[:database]
    config[:database] = File.expand_path(config[:database], Rails.root) if defined?(Rails.root)
    dirname = File.dirname(config[:database])
    Dir.mkdir(dirname) unless File.directory?(dirname)
  end

  db = SQLite3::Database.new(
    config[:database].to_s,
    :results_as_hash => true
  )

  db.busy_timeout(ConnectionAdapters::SQLite3Adapter.type_cast_config_to_integer(config[:timeout])) if config[:timeout]

  ConnectionAdapters::SQLite3Adapter.new(db, logger, config)
rescue Errno::ENOENT => error
  if error.message.include?("No such file or directory")
    raise ActiveRecord::NoDatabaseError.new(error.message)
  else
    raise error
  end
end