Module: ActiveRecord::AttributeMethods::PrimaryKey::ClassMethods

Relationships & Source Files
Defined in:	activerecord/lib/active_record/attribute_methods/primary_key.rb

Constant Summary

#primary_key rw

Defines the primary key field – can be overridden in subclasses.
#primary_key=(value) rw

Sets the name of the primary key column.

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

[ GitHub ]

# File 'activerecord/lib/active_record/attribute_methods/primary_key.rb', line 111


def primary_key
  if PRIMARY_KEY_NOT_SET.equal?(@primary_key)
    @primary_key = reset_primary_key
  end
  @primary_key
end

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"

[ GitHub ]

# File 'activerecord/lib/active_record/attribute_methods/primary_key.rb', line 165


def primary_key=(value)
  @primary_key        = derive_primary_key(value)
  @quoted_primary_key = nil
  @attributes_builder = nil
end

[ GitHub ]

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


def dangerous_attribute_method?(method_name)
  super && !ID_ATTRIBUTE_METHODS.include?(method_name)
end

[ GitHub ]

# File 'activerecord/lib/active_record/attribute_methods/primary_key.rb', line 100


def instance_method_already_implemented?(method_name)
  super || primary_key && ID_ATTRIBUTE_METHODS.include?(method_name)
end

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

[ GitHub ]

# File 'activerecord/lib/active_record/attribute_methods/primary_key.rb', line 124


def quoted_primary_key
  @quoted_primary_key ||= connection.quote_column_name(primary_key)
end