Unable to call rake task twice, with postgresql

[urzur]

Hello,

I have a rake task that looks like this:

namespace :db do
desc "Erase and fill database"
task :populate => :environment do

[A,B].each(&:delete_all)

A.populate 15 do |a|
  a.title = Populator.words(5..8)

    B.populate 3 do |b|
      b.a_id = a.id
      b.title = Populator.words(5..8)
    end#B

  end#A

end#task

end#namespace

Using sqlite3, whenever I call the rake task multiple times, everything works.
Using postgresql, first time works like a charm (asuming I just migrated the database) but the second+ times it fails. When looking at
A.all.to_a (using Rails 4)
B.all.to_a

I have data for both models but each record in b has an invalid id for a_id and associations are lost (ie. I cannot do a.bs)

obvious here a, b are places holders.

This seems to happen with postgresql and not sqlite3. Getting the same error on heroku (uses postresql) and in local machine

[GantMan]

I'm having the same issue.

Just doing a rake db:drop and rake db:setup puts me back at index 1, so it works. But I have to kill ALL tables with that drop.