rails 2.3.8 validates_uniqueness_of with:scope 不工作

Question

I'm using rails 2.3.8 and I have a model with two attributes I want to validate by.

I have version and file number and I need to validate uniqueness of the file number on update but only according to each individual unique version.

So I've tried

 validates_uniqueness_of :file_number, :scope => :version, :on => :update

I repeatedly get "File number has already been taken"

There is no special logic with the file number except for in a before_create where I add one to the count of items for that version.

EDIT: Here's the SQL that the server performs. http://pastie.org/private/ysbwtiyouhgqkjsjjbooa The id here is the id of the record I'm updating and the one returned from the query is another record.

Any ideas?

EDIT- I got it: SOLUTION:

Turns out the validation wasn't looking across a select list of mymodel records which would be defined by

mymodel belongs to project and project has_many mymodel

so with the following tweak it worked.

validates_uniqueness_of:file_number, :scope => [:version, :project_id], :on =>:update

Answer 1

Pasting solution as answer:

Turns out the validation wasn't looking across a select list of mymodel records which would be defined by

mymodel belongs to project and project has_many mymodel

so with the following tweak it worked.

validates_uniqueness_of:file_number, :scope => [:version, :project_id], :on =>:updat