I have this code
I have these options and if the user select anything except 'British Columbia' to give him error message that the province have to 'British Columbia'
I believe it will solve by using the model validation
<%= f.label :province ,"Province (required)"%><br>
<%= f.select(:province, [["Select One", ""],'Alberta','British Columbia','Manitoba','New Brunswick','Newfoundland and Labrador','Nova Scotia','Northwest Territories','Nunavut','Ontario','Prince Edward Island','Quebec','Saskatchewan','Yukon'], {}) %>
User.rb
validates :province, presence: "British Columbia"
You shouldn't use presence, it's the wrong validation. You should use inclusion:
validates :province, inclusion: { in: %w[British Columbia] }
You realize this is a nonsensical problem, right? What's the point of offering several alternatives in the view if the validation will only accept one?