ActiveRecord::Core

configurations()

Returns fully resolved ActiveRecord::DatabaseConfigurations object

📝 Source code

# File activerecord/lib/active_record/core.rb, line 77
      def self.configurations
        @@configurations
      end

🔎 See on GitHub

configurations=(config)

Contains the database configuration - as is typically stored in config/database.yml - as an ActiveRecord::DatabaseConfigurations object.

For example, the following database.yml…

development:
  adapter: sqlite3
  database: storage/development.sqlite3

production:
  adapter: sqlite3
  database: storage/production.sqlite3

…would result in ActiveRecord::Base.configurations to look like this:

#<ActiveRecord::DatabaseConfigurations:0x00007fd1acbdf800 @configurations=[
  #<ActiveRecord::DatabaseConfigurations::HashConfig:0x00007fd1acbded10 @env_name="development",
    @name="primary", @config={adapter: "sqlite3", database: "storage/development.sqlite3"}>,
  #<ActiveRecord::DatabaseConfigurations::HashConfig:0x00007fd1acbdea90 @env_name="production",
    @name="primary", @config={adapter: "sqlite3", database: "storage/production.sqlite3"}>
]>

📝 Source code

# File activerecord/lib/active_record/core.rb, line 71
      def self.configurations=(config)
        @@configurations = ActiveRecord::DatabaseConfigurations.new(config)
      end

🔎 See on GitHub

connection_handler()

📝 Source code

# File activerecord/lib/active_record/core.rb, line 117
      def self.connection_handler
        ActiveSupport::IsolatedExecutionState[:active_record_connection_handler] || default_connection_handler
      end

🔎 See on GitHub

connection_handler=(handler)

📝 Source code

# File activerecord/lib/active_record/core.rb, line 121
      def self.connection_handler=(handler)
        ActiveSupport::IsolatedExecutionState[:active_record_connection_handler] = handler
      end

🔎 See on GitHub

current_preventing_writes()

Returns the symbol representing the current setting for preventing writes.

ActiveRecord::Base.connected_to(role: :reading) do
  ActiveRecord::Base.current_preventing_writes #=> true
end

ActiveRecord::Base.connected_to(role: :writing) do
  ActiveRecord::Base.current_preventing_writes #=> false
end

📝 Source code

# File activerecord/lib/active_record/core.rb, line 180
      def self.current_preventing_writes
        connected_to_stack.reverse_each do |hash|
          return hash[:prevent_writes] if !hash[:prevent_writes].nil? && hash[:klasses].include?(Base)
          return hash[:prevent_writes] if !hash[:prevent_writes].nil? && hash[:klasses].include?(connection_class_for_self)
        end

        false
      end

🔎 See on GitHub

current_role()

Returns the symbol representing the current connected role.

ActiveRecord::Base.connected_to(role: :writing) do
  ActiveRecord::Base.current_role #=> :writing
end

ActiveRecord::Base.connected_to(role: :reading) do
  ActiveRecord::Base.current_role #=> :reading
end

📝 Source code

# File activerecord/lib/active_record/core.rb, line 143
      def self.current_role
        connected_to_stack.reverse_each do |hash|
          return hash[:role] if hash[:role] && hash[:klasses].include?(Base)
          return hash[:role] if hash[:role] && hash[:klasses].include?(connection_class_for_self)
        end

        default_role
      end

🔎 See on GitHub

current_shard()

Returns the symbol representing the current connected shard.

ActiveRecord::Base.connected_to(role: :reading) do
  ActiveRecord::Base.current_shard #=> :default
end

ActiveRecord::Base.connected_to(role: :writing, shard: :one) do
  ActiveRecord::Base.current_shard #=> :one
end

📝 Source code

# File activerecord/lib/active_record/core.rb, line 161
      def self.current_shard
        connected_to_stack.reverse_each do |hash|
          return hash[:shard] if hash[:shard] && hash[:klasses].include?(Base)
          return hash[:shard] if hash[:shard] && hash[:klasses].include?(connection_class_for_self)
        end

        default_shard
      end

🔎 See on GitHub

destroy_association_async_batch_size

Specifies the maximum number of records that will be destroyed in a single background job by the dependent: :destroy_async association option. When nil (default), all dependent records will be destroyed in a single background job. If specified, the records to be destroyed will be split into multiple background jobs.

📝 Source code

# File activerecord/lib/active_record/core.rb, line 47
      class_attribute :destroy_association_async_batch_size, instance_writer: false, instance_predicate: false, default: nil

🔎 See on GitHub

destroy_association_async_job()

The job class used to destroy associations in the background.

📝 Source code

# File activerecord/lib/active_record/core.rb, line 27
      def self.destroy_association_async_job
        if _destroy_association_async_job.is_a?(String)
          self._destroy_association_async_job = _destroy_association_async_job.constantize
        end
        _destroy_association_async_job
      rescue NameError => error
        raise NameError, "Unable to load destroy_association_async_job: #{error.message}"
      end

🔎 See on GitHub

enumerate_columns_in_select_statements

Force enumeration of all columns in SELECT statements. e.g. SELECT first_name, last_name FROM ... instead of SELECT * FROM ... This avoids PreparedStatementCacheExpired errors when a column is added to the database while the app is running.

📝 Source code

# File activerecord/lib/active_record/core.rb, line 87
      class_attribute :enumerate_columns_in_select_statements, instance_accessor: false, default: false

🔎 See on GitHub

logger

Accepts a logger conforming to the interface of Log4r or the default Ruby Logger class, which is then passed on to any new database connections made. You can retrieve this logger by calling logger on either an Active Record model class or an Active Record model instance.

📝 Source code

# File activerecord/lib/active_record/core.rb, line 22
      class_attribute :logger, instance_writer: false

🔎 See on GitHub

new(attributes = nil)

New objects can be instantiated as either empty (pass no construction parameter) or pre-set with attributes but not yet saved (pass a hash with key names matching the associated table column names). In both instances, valid attribute keys are determined by the column names of the associated table – hence you can’t have attributes that aren’t part of the table columns.

Example

# Instantiates a single new object
User.new(first_name: 'Jamie')

📝 Source code

# File activerecord/lib/active_record/core.rb, line 446
    def initialize(attributes = nil)
      @new_record = true
      @attributes = self.class._default_attributes.deep_dup

      init_internals
      initialize_internals_callback

      assign_attributes(attributes) if attributes

      yield self if block_given?
      _run_initialize_callbacks
    end

🔎 See on GitHub

<=>(other_object)

Allows sort on objects

📝 Source code

# File activerecord/lib/active_record/core.rb, line 633
    def <=>(other_object)
      if other_object.is_a?(self.class)
        to_key <=> other_object.to_key
      else
        super
      end
    end

🔎 See on GitHub

==(comparison_object)

Returns true if comparison_object is the same exact object, or comparison_object is of the same type and self has an ID and it is equal to comparison_object.id.

Note that new records are different from any other record by definition, unless the other record is the receiver itself. Besides, if you fetch existing records with select and leave the ID out, you’re on your own, this predicate will return false.

Note also that destroying a record preserves its ID in the model instance, so deleted models are still comparable.

Also aliased as: eql?

📝 Source code

# File activerecord/lib/active_record/core.rb, line 599
    def ==(comparison_object)
      super ||
        comparison_object.instance_of?(self.class) &&
        primary_key_values_present? &&
        comparison_object.id == id
    end

🔎 See on GitHub

clone

Identical to Ruby’s clone method. This is a “shallow” copy. Be warned that your attributes are not copied. That means that modifying attributes of the clone will modify the original, since they will both point to the same attributes hash. If you need a copy of your attributes hash, please use the dup method.

user = User.first
new_user = user.clone
user.name               # => "Bob"
new_user.name = "Joe"
user.name               # => "Joe"

user.object_id == new_user.object_id            # => false
user.name.object_id == new_user.name.object_id  # => true

user.name.object_id == user.dup.name.object_id  # => false

🔎 See on GitHub

connection_handler()

📝 Source code

# File activerecord/lib/active_record/core.rb, line 713
    def connection_handler
      self.class.connection_handler
    end

🔎 See on GitHub

dup

Duped objects have no id assigned and are treated as new records. Note that this is a “shallow” copy as it copies the object’s attributes only, not its associations. The extent of a “deep” copy is application specific and is therefore left to the application to implement according to its need. The dup method does not preserve the timestamps (created|updated)_(at|on) and locking column.

🔎 See on GitHub

encode_with(coder)

Populate coder with attributes about this record that should be serialized. The structure of coder defined in this method is guaranteed to match the structure of coder passed to the init_with method.

Example:

class Post < ActiveRecord::Base
end
coder = {}
Post.new.encode_with(coder)
coder # => {"attributes" => {"id" => nil, ... }}

📝 Source code

# File activerecord/lib/active_record/core.rb, line 555
    def encode_with(coder)
      self.class.yaml_encoder.encode(@attributes, coder)
      coder["new_record"] = new_record?
      coder["active_record_yaml_version"] = 2
    end

🔎 See on GitHub

eql?(comparison_object)

Alias for: ==

freeze()

Clone and freeze the attributes hash such that associations are still accessible, even on destroyed records, but cloned models will not be frozen.

📝 Source code

# File activerecord/lib/active_record/core.rb, line 622
    def freeze
      @attributes = @attributes.clone.freeze
      self
    end

🔎 See on GitHub

frozen?()

Returns true if the attributes hash has been frozen.

📝 Source code

# File activerecord/lib/active_record/core.rb, line 628
    def frozen?
      @attributes.frozen?
    end

🔎 See on GitHub

hash()

Delegates to id in order to allow two records of the same type and id to work with something like:

[ Person.find(1), Person.find(2), Person.find(3) ] & [ Person.find(1), Person.find(4) ] # => [ Person.find(1) ]

📝 Source code

# File activerecord/lib/active_record/core.rb, line 609
    def hash
      id = self.id

      if primary_key_values_present?
        self.class.hash ^ id.hash
      else
        super
      end
    end

🔎 See on GitHub

init_with(coder, &block)

Initialize an empty model object from coder. coder should be the result of previously encoding an Active Record model, using encode_with.

class Post < ActiveRecord::Base
end

old_post = Post.new(title: "hello world")
coder = {}
old_post.encode_with(coder)

post = Post.allocate
post.init_with(coder)
post.title # => 'hello world'

📝 Source code

# File activerecord/lib/active_record/core.rb, line 473
    def init_with(coder, &block)
      coder = LegacyYamlAdapter.convert(coder)
      attributes = self.class.yaml_encoder.decode(coder)
      init_with_attributes(attributes, coder["new_record"], &block)
    end

🔎 See on GitHub

inspect()

Returns the contents of the record as a nicely formatted string.

📝 Source code

# File activerecord/lib/active_record/core.rb, line 718
    def inspect
      # We check defined?(@attributes) not to issue warnings if the object is
      # allocated but not initialized.
      inspection = if defined?(@attributes) && @attributes
        attribute_names.filter_map do |name|
          if _has_attribute?(name)
            "#{name}: #{attribute_for_inspect(name)}"
          end
        end.join(", ")
      else
        "not initialized"
      end

      "#<#{self.class} #{inspection}>"
    end

🔎 See on GitHub

pretty_print(pp)

Takes a PP and prettily prints this record to it, allowing you to get a nice result from pp record when pp is required.

📝 Source code

# File activerecord/lib/active_record/core.rb, line 736
    def pretty_print(pp)
      return super if custom_inspect_method_defined?
      pp.object_address_group(self) do
        if defined?(@attributes) && @attributes
          attr_names = self.class.attribute_names.select { |name| _has_attribute?(name) }
          pp.seplist(attr_names, proc { pp.text "," }) do |attr_name|
            pp.breakable " "
            pp.group(1) do
              pp.text attr_name
              pp.text ":"
              pp.breakable
              value = _read_attribute(attr_name)
              value = inspection_filter.filter_param(attr_name, value) unless value.nil?
              pp.pp value
            end
          end
        else
          pp.breakable " "
          pp.text "not initialized"
        end
      end
    end

🔎 See on GitHub

readonly!()

Marks this record as read only.

customer = Customer.first
customer.readonly!
customer.save # Raises an ActiveRecord::ReadOnlyRecord

📝 Source code

# File activerecord/lib/active_record/core.rb, line 709
    def readonly!
      @readonly = true
    end

🔎 See on GitHub

readonly?()

Returns true if the record is read only.

📝 Source code

# File activerecord/lib/active_record/core.rb, line 650
    def readonly?
      @readonly
    end

🔎 See on GitHub

slice(*methods)

Returns a hash of the given methods with their names as keys and returned values as values.

topic = Topic.new(title: "Budget", author_name: "Jason")
topic.slice(:title, :author_name)
=> { "title" => "Budget", "author_name" => "Jason" }

🔎 See on GitHub

strict_loading!(value = true, mode: :all)

Sets the record to strict_loading mode. This will raise an error if the record tries to lazily load an association.

user = User.first
user.strict_loading! # => true
user.address.city
=> ActiveRecord::StrictLoadingViolationError
user.comments.to_a
=> ActiveRecord::StrictLoadingViolationError

Parameters

value - Boolean specifying whether to enable or disable strict loading.
:mode - Symbol specifying strict loading mode. Defaults to :all. Using :n_plus_one_only mode will only raise an error if an association that will lead to an n plus one query is lazily loaded.

Examples

user = User.first
user.strict_loading!(false) # => false
user.address.city # => "Tatooine"
user.comments.to_a # => [#<Comment:0x00...]

user.strict_loading!(mode: :n_plus_one_only)
user.address.city # => "Tatooine"
user.comments.to_a # => [#<Comment:0x00...]
user.comments.first.ratings.to_a
=> ActiveRecord::StrictLoadingViolationError

📝 Source code

# File activerecord/lib/active_record/core.rb, line 688
    def strict_loading!(value = true, mode: :all)
      unless [:all, :n_plus_one_only].include?(mode)
        raise ArgumentError, "The :mode option must be one of [:all, :n_plus_one_only] but #{mode.inspect} was provided."
      end

      @strict_loading_mode = mode
      @strict_loading = value
    end

🔎 See on GitHub

strict_loading?()

Returns true if the record is in strict_loading mode.

📝 Source code

# File activerecord/lib/active_record/core.rb, line 655
    def strict_loading?
      @strict_loading
    end

🔎 See on GitHub

strict_loading_n_plus_one_only?()

Returns true if the record uses strict_loading with :n_plus_one_only mode enabled.

📝 Source code

# File activerecord/lib/active_record/core.rb, line 700
    def strict_loading_n_plus_one_only?
      @strict_loading_mode == :n_plus_one_only
    end

🔎 See on GitHub

values_at(*methods)

Returns an array of the values returned by the given methods.

topic = Topic.new(title: "Budget", author_name: "Jason")
topic.values_at(:title, :author_name)
=> ["Budget", "Jason"]

🔎 See on GitHub

ActiveRecord::Core

Active Record Core

Namespace

Module

Class

Methods

Attributes

Class Public methods

configurations()

configurations=(config)

connection_handler()

connection_handler=(handler)

current_preventing_writes()

current_role()

current_shard()

destroy_association_async_batch_size

destroy_association_async_job()

enumerate_columns_in_select_statements

logger

new(attributes = nil)

Example

Instance Public methods

<=>(other_object)

==(comparison_object)

clone

connection_handler()

dup

encode_with(coder)

eql?(comparison_object)

freeze()

frozen?()

hash()

init_with(coder, &block)

inspect()

pretty_print(pp)

readonly!()

readonly?()

slice(*methods)

strict_loading!(value = true, mode: :all)

Parameters

Examples

strict_loading?()

strict_loading_n_plus_one_only?()

values_at(*methods)