Using: Ruby 1.9.2, Rails 3.0.9, SQLite3
I am seeing some odd behavior when saving an integer field in
activerecord. I have setup a test scenario in the Rails console using
the following migration and corresponding model:
class CreateMyobjs < ActiveRecord::Migration
def self.up
create_table :myobjs do |t|
t.integer :int, :default => 0, :null => false
t.timestamps
end
end
def self.down
drop_table :myobjs
end
end
In the Rails console (line numbers added by me):
1 ruby-1.9.2-p290 :001 > o = Myobj.new
2 => #<Myobj id: nil, int: 0, created_at: nil, updated_at: nil>
3 ruby-1.9.2-p290 :002 > o.save
4 => true
5 ruby-1.9.2-p290 :003 > o
6 => #<Myobj id: 1, int: 0, created_at: "2011-10-12 19:59:17",
updated_at: "2011-10-12 19:59:17">
7 ruby-1.9.2-p290 :004 > o.int = ''
8 => ""
9 ruby-1.9.2-p290 :005 > o
10 => #<Myobj id: 1, int: nil, created_at: "2011-10-12 19:59:17",
updated_at: "2011-10-12 19:59:17">
11 ruby-1.9.2-p290 :006 > o.save
12 => true
13 ruby-1.9.2-p290 :007 > o
14 => #<Myobj id: 1, int: nil, created_at: "2011-10-12 19:59:17",
updated_at: "2011-10-12 19:59:17">
15 ruby-1.9.2-p290 :008 > o2 = Myobj.find(1)
16 => #<Myobj id: 1, int: 0, created_at: "2011-10-12 19:59:17",
updated_at: "2011-10-12 19:59:17">
In lines 1-6 I create a new Myobj, save it and verify its attributes,
at this point o.int = 0, the default value from the database.
In lines 7-10 I set the value of o.int to '' (blank string), which
activerecord translates to nil, since it is an integer field.
Lines 11-12 successfully saves o with o.int set to nil, this save
*should* raise an InvalidStatement exception from the database, but it
does not!
Lines 13-14 verify's that the apparently saved o object still thinks
the int field is nil.
Line 15-16 lookups up the record from the database and shows that the
int field is not actually nil, but rather is still 0. It is apparent
that the original o object did not save the int attribute properly to
the database.
Trying to do the same thing when o.int starts ut as non-zero results
in the following:
17 ruby-1.9.2-p290 :009 > o.int = 3
18 => 3
19 ruby-1.9.2-p290 :010 > o.save
20 => true
21 ruby-1.9.2-p290 :011 > o
22 => #<Myobj id: 1, int: 3, created_at: "2011-10-12 19:59:17",
updated_at: "2011-10-12 20:08:00">
23 ruby-1.9.2-p290 :012 > o.int = nil
24 => nil
25 ruby-1.9.2-p290 :013 > o.save
26 ActiveRecord::StatementInvalid: SQLite3::ConstraintException:
myobjs.int may not be NULL: UPDATE "myobjs" SET "int" = NULL,
"updated_at" = '2011-10-12 20:08:13.550661' WHERE "myobjs"."id" =
1 ...
I wont give a step-by-step description of this one, but as you can see
the expected database exception is raised.
>From these tests it appears that activerecord's save method is not
updating integer fields when they change from 0 to nil. I think it is
likely that this is because it is internally coercing the value of the
integer field using to_i, and of course nil.to_i == 0.
Can anyone else confirm this behavior or think of a good reason why it
would be like this?
Thanks,
Chris
--
You received this message because you are subscribed to the Google Groups "Ruby
on Rails: Talk" group.
To post to this group, send email to [email protected].
To unsubscribe from this group, send email to
[email protected].
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk?hl=en.
