Rails3 & ActiveRecord::Relation - Arel and OR

I have some scopes definied in a Model called Events. Now I need join them using OR operator. I’m using Rails3 and I’m a bit confused with ActiveRelation & Arel and how and how I should use this

scope :issues,   where(:subject_type =>  "Issue")
scope :for_company, lambda {|company| joins(:user)
                                      .where(:users => { :company_id => company.id })
                                      .includes(:user)}

How I can get events

for_company(x) OR issues

When I try Events.for_company(X).or(issues) I get an error

Events.for_company(Company.find(1)).or(Events.issues)

NoMethodError: undefined method `or' for #ActiveRecord::Relation

using Events.for_company(Company.find(1)).arel.or(Events.issues) I get

NoMethodError: undefined method `or' for #Arel::SelectManager

I w开发者_Python百科ant get all events that are issues or where user is from a determined company.

select * from events 
         join users  
           on events.user_id = users.id 
        where users.company_id = 1 
           or events.subject_type = "Issues"

Thanks.

Ruby on Rails 3 howto make 'OR' condition
Rails3: combine scope with OR

Event.for_company(Company.find(1)).issues