Question

I have the following scope:

scope :this_month, :conditions => ["created_at >= ?", Date.today.beginning_of_month]

Which makes the SQL output of a.response_sets.this_month.to_sql:

SELECT "response_sets".* FROM "response_sets" WHERE created_at >= '2012-05-01'

But since today is actually June 1, that date seems wrong. So, I tried bypassing the scope and just doing a condition directly, like so:

a.response_sets.where(["created_at >= ?", Date.today.beginning_of_month]).to_sql

Which then, outputs:

SELECT "response_sets".* FROM "response_sets" WHERE created_at >= '2012-06-01'

Which is correct. So why is there a difference between doing Date.today.beginning_of_month in a scope and doing it directly in where?

Answer 1

When working with dates in scopes you should use a lambda so the scope gets evaluated every time it is called:

scope :this_month, -> { where("created_at >= ?", Date.today.beginning_of_month) }