How do I validate two fields for uniqueness

Question

I need to validate the uniqueness of two fields in an object (row) before I add them. Employee_id and area_id are the two fields in my emp_area table. There can be multiple records with the same employee_id and multiple records with the same area_id, but no two records can have the same employee_id and the same area_id. This is sort of like two fields making up a primary-key or unique-key.

How can I do this.

Thanks

possible duplicate of [How do you validate uniqueness of a pair of ids in Ruby on Rails?](http://stackoverflow.com/questions/923796/how-do-you-validate-uniqueness-of-a-pair-of-ids-in-ruby-on-rails) — Ciro Santilli OurBigBook.com, Jul 01 '14 at 16:00

score 99 · Answer 1 · edited May 23 '17 at 11:47

99

what about this solution Validate combined values

validates :employee_id, uniqueness: { scope: :area_id }

edited May 23 '17 at 11:47

Community

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answered Apr 14 '11 at 06:12

Naveed

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This seems to be preferred over `validates_uniqueness_of` as it allows you set multiple validations on the same form, e.g. `presence: true`. – Joshua Pinter Apr 27 '15 at 19:26
For correct highlight of the error messages I created also validates :area_id, uniqueness: { scope: employee_id } – Mauro Aug 05 '16 at 14:28

score 69 · Answer 2 · answered Oct 27 '09 at 20:00

69

validates_uniqueness_of :employee_id, :scope => :area_id

answered Oct 27 '09 at 20:00

JRL

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How do I validate two fields for uniqueness

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