Strange behaviour

rubyonrails-talk
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

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)... ?

=> 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.

-- Daniel Bush

3

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

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.

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

Fred

5

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.