Hi,
validates_uniqueness_of :title, :scope => where(posted_on:

{ "$gt" => posted_on.beginning_of_day, "$lte" => posted_on.end_of_day})
is not working. Being title is a string field and posted_on is a datetime field. Actual problem is validate uniqueness of title in a day.

If found an alternate solution.
validates_uniqueness_of :title, if: -> { Ad.where(title: title, posted_on: { "$gt" => posted_on.beginning_of_day, "$lte" => posted_on.end_of_day}

).size > 0 }

Can you suggest a better solution.