tag迁移 -- Andersen_Fan

migration.rb

# in db
update knowledges set auto_tags = tags;
update questions  set auto_tags = tags;
alter table tags rename to tags_bak;
rake db:migrate

#TODO? for identity/timeline/category tags? 

# in rails console
class TagBak < ActiveRecord::Base
  set_table_name "tags_bak"
end
class CategoryBase < ActiveRecord::Base
  set_table_name "category_bases"
end
class Identity < CategoryBase
end
class TimeLine < CategoryBase
end
class Category < CategoryBase
end
# for knowledges
# delete the tags column of table knowledges
Knowledge.all.each do |m| m.tag_list=m.auto_tags.split(",").collect{|t| begin;TagBak.find(t).name if t and !t.empty?;end}.join(",");m.save; end;puts

# for questions
# delete the tags column of table questions
Question.all.each do |m| m.tag_list=m.auto_tags.split(",").collect{|t| begin;TagBak.find(t).name if t and !t.empty?;end}.join(",");m.save; end;puts

#更新所有timeline：
TimeLine.all.each do |m|
  Tag.find_by_name(m.name).taggings.each do |tgg|
    tgg.context="timelines";
    tgg.save;
  end;
end
#更新所有category:
Category.all.each do |m|
  Tag.find_by_name(m.name).taggings.each do |tgg|
    tgg.context="categories";
    tgg.save;
  end;
end
#更新所有identity:
Identity.all.each do |m|
  Tag.find_by_name(m.name).taggings.each do |tgg|
    tgg.context="identities";
    tgg.save;
  end;
end