On Wed, Feb 29, 2012 at 3:53 PM, LED <[email protected]> wrote: > hi im new in rails and starting to develop my application which is a > online reservation im just wondering if there is a way in Ruby on > rails to group a validation > > ei. i want to validate the uniqueness of date first in the database > and check what are the timeStart and endTime entries in that > particular date and validate its uniqueness(timeStart and endTime) > base on the date? is it possible in validation or do i have to make a > controller or method for it? > > to sum up my application can book a reservation in a same date but not > in a same date and time > > sorry for my bad english my Reservation database is: > 0 id INTEGER 1 1 > 1 lname varchar(25 1 0 > 2 fname varchar(25 1 0 > 3 contactnum integer 1 0 > 4 email varchar(10 1 0 > 5 date date 1 '2012-03-0 0 > 6 timeStart time 1 '--- > :hour 0 > 7 timeEnd time 1 '--- > :hour 0 > 8 numGuest integer 0 5 0 > 9 totalCost decimal(2) 0 0 > 10 confirm boolean 0 'f' 0 > 11 created_at datetime 0 0 > 12 updated_at datetime 0 0 >
1) Check the rails guide on validations http://guides.rubyonrails.org/active_record_validations_callbacks.html section 3.10 The part on "scope" might be helpful (e.g. uniqueness on a timeStart, scoped to date) 2) This validaton (or any validation that is outside of the db) can still fail when 2 separate processes (e.g. 2 Passenger processes) are checking at the same time (a race condition). Read e.g. the section Concurrency and integrity in http://api.rubyonrails.org/classes/ActiveRecord/Validations/ClassMethods.html#method-i-validates_uniqueness_of If you are building a "serious" reservation system and you do never ever want to promise the same resource to 2 different users at the same timeslot, you better understand that problem. 3) If your timeStart and endTime are intended as "times in a day" and not an absolute time in history, you might use my 'relativity' gem https://github.com/petervandenabeele/relativity It also has a DayTimeRange that may be useful for what you are trying to do. If you use a standardized separator you could even write an equality or overlap comparator for DayTimeRange class. HTH, Peter -- 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.
