Scope with association .any?

Question

I have two models, employees, and departments. Employes belong Departments through Positions. In a select tag I'd like to list only departments that have employees in them.

Right now I have:

@current_company.departments.collect {|d| [d.title, d.id] if d.employees.any?}

Which leaves me with a couple of nil select options. I thought I could write a scope for depmartments that would work like @current_company.departments.with_employees:

scope :with_employees, :where => (self.employees.any?)

I realize that won't work, but I'm stuck on what I should do.

score 7 · Accepted Answer · answered Apr 18 '11 at 18:53

7

Remember that a join is an inner join, which does precisely what you want - writing the join as a scope...

scope :with_employees, :joins => :employees

answered Apr 18 '11 at 18:53

smathy

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+1 for reusability, brilliant clarity, extensibility, simplicity and efficiency. – Blake Taylor Apr 19 '11 at 14:10
I forgot to mention that employees belong to departments :through => :positions. Still applicable? – Jarrett Apr 19 '11 at 23:12
Hopefully you've tried it already and found out that yes, it works through a join table too. Time to accept my answer now, feed me ;) – smathy Apr 20 '11 at 19:02

score 0 · Answer 2 · answered Apr 18 '11 at 19:14

0

If you don't need nil select options why you can't use .compact method?

@current_company.departments.collect {|d| [d.title, d.id] if d.employees.any?}.compact

answered Apr 18 '11 at 19:14

Vasiliy Ermolovich

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score 0 · Answer 3 · answered Apr 18 '11 at 19:30

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Or yet another way to do it...

@current_company.departments.reject {|d| d.employees.empty?}.collect {|d| [d.title, d.id]}

The beauty of Ruby is there are so many ways to do anything ;)

answered Apr 18 '11 at 19:30

Jim Morris

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Scope with association .any?

3 Answers3