>
id<><> ( NOT database generated )
max_weight
drive
In my model I have implemented the semantic of inheritance between
System and Lifter in this way:
class System < ActiveRecord::Base
has_one :lifter
:foreign_key=>:id,
:dependent=>:destroy,
:autosave=>:true
delegate :drive, :drive=, :max_weight,:max_weight=,:to=>:lifter
trick for polymorphic query
end
class Lifter
belongs_to :system,
:foreign_key=>:id,
:dependent=>:destroy,
:autosave=>:true
delegate :manufacturer,
:manufacturer=,
:serial_number,
:serial_number=,
:installation_date,
:installation_date, :to=>:system
alias system_without_build system
def system
system_without_build || build_system
end
end
In the client code :
lifter = Lifter.new
lifter.id=1327
lifter.installation_date= Date.parse(“7/8/2010”)
lifter.manufacturer=“FooLift”
lifter.serial_number=“1324AA”
lifter.drive=“Automatic”
lifter.max_weight=1200
lifter.save!
performs this wrong (in id) INSERTS:
INSERT INTO systems
(installation_date, manufacturer, serial_number)
VALUES (?, ?, ?)
[
[“installation_date”, Sun, 07 Aug 2010],
[“manufacturer”, “FooLift”],
[“serial_number”, “1324AA”]
]
INSERT INTO lifters
(drive, id, max_weight)
VALUES (?, ?, ?)
[
[“drive”, “Automatic”], [“id”, 0], [“max_weight”, 1200]
]
seems to loose the pre-assigned id setting (id=1327) and attempts to
fetch a database generated id. In other words after saving, lifter.id ==
0
I didn’t understand why, can someone help me please?
Thanks