On Wed, Dec 14, 2011 at 12:06, JavierQQ <[email protected]> wrote: > I have a Scale model with this fields > group_id > name > min_val > max_val > category > > for example the first record will have as > - min_val : 0 > - max_val : 10 > > and the next values shouldn't be in that range. > > I discovered that I can do this.... > > validates :min_val, :uniqueness => { :scope => :group_id}, > > But I want to validate that the new min/max value is not in a already > saved record > > Is there a rails way to do that?
If I understand rightly, what you want to do is to divide the space up into non-overlapping ranges. Is that correct? If so, then you could use a validator function that checks the new record against all saved records to see if there is overlap. That would be rather inefficient, though, so if you're adding new Scales frequently, it could slow down the system. If adding Scales is very rare, then remember the old maxim: all algorithms are fast, for sufficiently small values of N. ;-) Alternately, you could just forget about max and just record the min, with the implied max being just below the min of the next group when sorted by min. That would also ensure you have no holes, except below the lowest min. However, that could be less efficient in usage (finding the right range for a value) because you'd have to make sure that not only is it above this min, but there are no higher mins it's below.... -Dave -- LOOKING FOR WORK! What: Ruby (on/off Rails), Python, other modern languages. Where: Northern Virginia, Washington DC (near Orange Line), and remote work. See: davearonson.com (main) * codosaur.us (code) * dare2xl.com (excellence). Specialization is for insects. (Heinlein) - Have Pun, Will Babble! (Aronson) -- 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.
