scinote-web/db/migrate/20160425133500_add_counter_cache_to_protocols.rb
2017-06-30 10:23:28 +02:00

15 lines
492 B
Ruby

class AddCounterCacheToProtocols < ActiveRecord::Migration[4.2]
def up
add_column :protocols, :nr_of_synced_children, :integer, default: 0
# Okay, now initialize the values of synced children
Protocol.find_each do |protocol|
children_count = select_value("SELECT COUNT(*) FROM protocols WHERE parent_id=#{protocol.id};")
protocol.update(nr_of_synced_children: children_count)
end
end
def down
remove_column :protocols, :nr_of_synced_children
end
end