How do I force ActiveRecord to reload a class?
I'm creating a bunch of migrations, some of which are standard "create table" or "modify table" migrations, and some of which modify data. I'm using my actual ActiveRecord models to modify the data, a la:
Blog.all.each do |blog|
update_some_blog_attributes_to_match_new_schema
end
The problem is that if I load the Blog class, then modify the table, then use the Blog class again, the models have the old table definitions, and cannot save to the new table. Is there a way to reload the classes and their attribute definitions so I can reuse them?
The answer is yes!
Blog.reset_column_information
I always used new models in migrations
MyBlog < ActiveRecord::Base
set_table_name 'blogs'
end
def self.up
MyBlog.all.each do |blog|
update_some_blog_attributes_to_match_new_schema
end
end
But Blog.reset_column_information
is more convenient.
Create new instances:
Old_blogs = Blog.all
# change/modify db table in here
New_blogs = Blog.all # this should be reloaded or you could use the .reload on this
# change information, load old into new
ex.
Old_blogs.each do |blog|
New_blogs.find(blog.id).title = blog.title
end