Methods

Constants

ID_ATTRIBUTE_METHODS = %w(id id= id? id_before_type_cast id_was id_in_database id_for_database).to_set
PRIMARY_KEY_NOT_SET = BasicObject.new

Instance Public methods

dangerous_attribute_method?(method_name)

📝 Source code 
# File activerecord/lib/active_record/attribute_methods/primary_key.rb, line 75
          def dangerous_attribute_method?(method_name)
            super && !ID_ATTRIBUTE_METHODS.include?(method_name)
          end
🔎 See on GitHub

instance_method_already_implemented?(method_name)

📝 Source code 
# File activerecord/lib/active_record/attribute_methods/primary_key.rb, line 71
          def instance_method_already_implemented?(method_name)
            super || primary_key && ID_ATTRIBUTE_METHODS.include?(method_name)
          end
🔎 See on GitHub

primary_key()

Defines the primary key field – can be overridden in subclasses. Overwriting will negate any effect of the primary_key_prefix_type setting, though.

📝 Source code 
# File activerecord/lib/active_record/attribute_methods/primary_key.rb, line 82
          def primary_key
            reset_primary_key if PRIMARY_KEY_NOT_SET.equal?(@primary_key)
            @primary_key
          end
🔎 See on GitHub

primary_key=(value)

Sets the name of the primary key column.

class Project < ActiveRecord::Base
  self.primary_key = 'sysid'
end

You can also define the primary_key method yourself:

class Project < ActiveRecord::Base
  def self.primary_key
    'foo_' + super
  end
end

Project.primary_key # => "foo_id"
📝 Source code 
# File activerecord/lib/active_record/attribute_methods/primary_key.rb, line 133
          def primary_key=(value)
            @primary_key = if value.is_a?(Array)
              @composite_primary_key = true
              include CompositePrimaryKey
              @primary_key = value.map { |v| -v.to_s }.freeze
            elsif value
              -value.to_s
            end
            @quoted_primary_key = nil
            @attributes_builder = nil
          end
🔎 See on GitHub

quoted_primary_key()

Returns a quoted version of the primary key name, used to construct SQL statements.

📝 Source code 
# File activerecord/lib/active_record/attribute_methods/primary_key.rb, line 94
          def quoted_primary_key
            @quoted_primary_key ||= adapter_class.quote_column_name(primary_key)
          end
🔎 See on GitHub