How to sort list of object?

Hi, I want sort list of object by field “num”.
I try
@blocks = Block.find_all
@blocks.collect{|block| block.attributes.sort_by{|item| item[“num”]}}
but I get
TypeError: can’t convert String into Integer
from (irb):37:in []' from (irb):37 from ./script/../config/../config/../vendor/rails/activerecord/lib/active_record/base.rb:2068:insort_by’
from (irb):37:in each' from (irb):37:insort_by’
from (irb):37
from (irb):37:in `collect’
from (irb):37

How to do it correctly?

You could do:
@blocks = Block.find(:all)
@blocks.sort! {|a,b| a.num<=> b.num}

thanks