class ActiveRecord::ConnectionAdapters::TableDefinition

def new_column_definition(name, type, **options) # :nodoc:
  if integer_like_primary_key?(type, options)
    type = integer_like_primary_key_type(type, options)
  end
  type = aliased_types(type.to_s, type)
  if @conn.supports_datetime_with_precision?
    if type == :datetime && !options.key?(:precision)
      options[:precision] = 6
    end
  end
  options[:primary_key] ||= type == :primary_key
  options[:null] = false if options[:primary_key]
  create_column_definition(name, type, options)
end