The uniqueness for a field

Rails 3.1.3

Say, I have tables, Video and Script. Their association is

Video:1 --- n:Script

Also, Script has a field called 'value', (which is decimal, but the type is not important here).

I want every 'value' to be unique for EACH Video. In other words,

Video1 : script-value=1, script-value=2, script-value=4 ...

is OK. But NOT

Video1 : script-value=2, script-value=2, script-value=4 ...

If I set ':value, uniqueness => true' in Script.rb, a critical problem occurs. script-value s are unique for EACH Video, but they are not for all Videos.

Video1 : script-value:1, script-value:2, script-value:4 ... Video2 : script-value:1, script-value:7, script-value:9 ... ...

Video1 and Video2 has the same script-values (=1), from which 'uniqueness => true' setting prevents.

Is there anyway to allow Videos to have the same 'value's, which however are distinct from each other among the values that a single Video possesses?

soichi

GIYF: How to validate uniqueness in Rails 3 Model if I want to check if there is a 2-field combination? - Stack Overflow

Thanks!

  validates :value, :uniqueness => { :scope => :video_id }

solves the problem.

soichi