Backfilling history

The basic workflow is:

Have a sorted array like this:

data = [
    {value: 1, from: '2010-01-01 00:00:00', to: '2011-01-01 00:00:00'},
    {value: 2, from: '2011-01-01 00:00:00', to: '2012-01-01 00:00:00'},
    {value: 3, from: '2012-01-01 00:00:00', to: '2013-01-01 00:00:00'},
    {value: 4, from: '2013-01-01 00:00:00', to: '2014-01-01 00:00:00'},
    {value: 5, from: '2014-01-01 00:00:00', to: '2015-01-01 00:00:00'}
    {value: 6, from: '2015-01-01 00:00:00', to: nil}
]

Wipe out the tables

Item.delete_all
Item::History.delete_all

Fill from the past:

record = Item.new
data.each do |d|
    record.value = d[:value]
    record.save!
    h = record.history.first
    h.class.amend_period!(h.hid, d[:from], d[:to])
end