[Rails Tip] DataMapper M:M Association Bug and Workaround

ifredwu@gmail.com (Fred Wu) — Mon, 26 Apr 2010 23:35:00 +0000

So for instance, the following code would generate an SQL error:

type.jobs.all(:"country.name".like => "%#{params[:location]}%")

There is a workaround, however the workaround requires manual looping of the dataset thus produces N+1 queries.

type.jobs.all.reject do |job|
! job.country.name.downcase.include?(params[:location].downcase)
end

But at least it works. ;)

]]>

[Rails Tip] DataMapper Timestamps Bug and Workaround

ifredwu@gmail.com (Fred Wu) — Mon, 19 Apr 2010 08:22:00 +0000

It has been confirmed by DataMapper’s core developer Martin Gamsjaeger (snusnu) that it is a bug.

In short, created_[at|on] can be manually overridden, but updated_[at|on] cannot.

The workaround is simple, do it in two steps, for example:

job = Job.create(
  title: "Web Developer",
  created_at: Time.now - 2
)
job.update!(updated_at: Time.now - 1)

Please check the bug ticket to see when it’s getting fixed.

]]>