Strange behaviour

Rails
1

I have the following relationships:

Document :has_many Proposals :has_many ProposalVersions.

This fails:

Document.first.proposals.first.proposal_versions.size
=> 0

But this works:

Proposal.find(1).proposal_versions.size
=> 2

Here’s the SQL from the first statement:

SELECT count(*) AS count_all FROM “proposal_versions” WHERE
(“proposal_versions”.proposal_id = 2)

The failing SQL in the first example seems really dangerous, because
it apparently picks an ID at random (and this obviously works also
with non-count queries, resulting in possibly returning the wrong set
of data:

Where does the ‘2’ come from? Neither Document or Proposal has ID 2,
they’re both ID 1.

Is this expected behaviour?

I’m on rails 2.2.1 (eh, 2.2 RC2). Linux. SQlite.

2

On Nov 17, 11:56 pm, sigvei [email protected] wrote:

I have the following relationships:

Document :has_many Proposals :has_many ProposalVersions.

This fails:>> Document.first.proposals.first.proposal_versions.size

Do you mean Document.find(:first)… ?

(“proposal_versions”.proposal_id = 2)

I’m on rails 2.2.1 (eh, 2.2 RC2). Linux. SQlite.

– Daniel B.

3

On 17 Nov, 14:38, Daniel B. [email protected] wrote:

On Nov 17, 11:56 pm, sigvei [email protected] wrote:

I have the following relationships:

Document :has_many Proposals :has_many ProposalVersions.

This fails:>> Document.first.proposals.first.proposal_versions.size

Do you mean Document.find(:first)… ?

ActiveRecord::Base::first is a convenience wrapper for
ActiveRecord::Base::find(:first), according to the API. So I can’t
quite see why that should make a difference.

4

On Nov 18, 1:19 am, sigvei [email protected] wrote:

Do you mean Document.find(:first)… ?

ActiveRecord::Base::first is a convenience wrapper for
ActiveRecord::Base::find(:first), according to the API. So I can’t
quite see why that should make a difference.

Sorry. Wasn’t familiar with it. Hard to imagine rails putting in a
random id.
Can only surmise that
Document.first.proposals.first.id==2
I don’t think any order is guaranteed either unless you’ve
specified :order somewhere so it may change randomly depending on your
database. Maybe you added a new proposal with no proposal versions in
addition to proposal with id=1. Or a new document even.

–
Daniel B.

5

On 17 Nov 2008, at 14:19, sigvei wrote:

Do you mean Document.find(:first)… ?

ActiveRecord::Base::first is a convenience wrapper for
ActiveRecord::Base::find(:first), according to the API. So I can’t
quite see why that should make a difference.

is there a document/proposal with id=2 (you’ve sort of implied that
there isn’t, but I’m not quite sure)

Fred