唯一性验证无效

Question

I am trying to apply validation of uniqueness to the field name custom_link. But it is allowing to add same values in the field. Following is my model:

class Gallery < ActiveRecord::Base
....
validates :custom_link, uniqueness: true
....
end

This is my code of controller:

def update
      respond_to do |format|
      if @gallery.update(gallery_params)
        format.html { redirect_to galleries_galleryhome_path(id: params[:id]), notice: 'Gallery was successfully updated.' }
        format.json { render :show, status: :ok, location: @gallery }
      else
        format.html { render :edit }
        format.json { render json: @gallery.errors, status: :unprocessable_entity }
      end
    end   end
private:

def gallery_params
      params.require(:gallery).permit(:name, :shoot_date, :release_date, :expiration_date, :archive,:gallery_layout_id, :contact_id,:status, :cover_url,:gallery_photo_id, photos_attributes: [:image]).merge(brand_id: current_brand.id,user_id: current_user.id)
    end

Getting no idea why it is not working. Can anyone help me?

Answer 1

Try considering case.

validates :custom_link, uniqueness: {case_sensitive: false}

Can you provide an example of what is allowed to be created more than once?

When are you creating the same value, on new creation, on update of an existing object, etc?

Answer 2

You should add a unique index in your DB, as stated in: http://guides.rubyonrails.org/active_record_validations.html#uniqueness

2.11 uniqueness This helper validates that the attribute's value is unique right before the object gets saved. It does not create a uniqueness constraint in the database, so it may happen that two different database connections create two records with the same value for a column that you intend to be unique. To avoid that, you must create a unique index on both columns in your database. See the MySQL manual for more details about multiple column indexes.

Add a migration with that constraint as follow:

rails g migration add_uniqueness_to_custom_link

Then write the new index:

self.change
   add_index :galleries, :custom_link, unique: true
end

And finally: rake db:migrate