In RoR, it is pretty common mistake for new people to load a class and assiocations like this# the solution to eager load
# The bellow generates an insane amount of queries
# post has many comments
# If you have 10 posts with 5 comments each
# this will run 11 queries
posts = Post.find(:all)
posts.each do |post|
post.comments
end
The solution is pretty simple to eager load
# should be 2 queries
# no matter how many posts you have
posts = Post.find(:all, :include => :comments) # runs a query to get all the comments for all the posts
posts.each do |post|
post.comments # runs a query to get the comments for that post
end
But what if you don't have access to the class methods, and only have access to a collection of instance methods.
Then you are stuck with the query intensive lazy loading.
Is there a way to minimize queries to get all the comments for the collection of posts, from the collection of instances?
Addition for Answer (also added to the code above)
So to eager load from what I can see in the rdoc for rails is a class method on any extension of ActiveRecord::Associations, the problem is say you you don't have the ability to use a class method, so you need to use some sort of instance method
a code example of what I think it would look like would be is something like
post = Posts.find(:all)
posts.get_all(:comments) # runs the query to build comments into each post without the class method.
