NOT work at me, i did same things like you. And at Group.find(:all).map { |g| g.users.map(&:email) } it says : NoMethodError: undefined method 'map' for #<User:0x47d4d18>
I am using Rails 1.2.3 & Ruby 1.8.5 & OS XP. Disconnect Riand[FX] Rie! <[EMAIL PROTECTED]> wrote: ;)) Look at the last line, that's the solution $ script/console Loading development environment (Rails 2.0.2) >> Group.count => 1 >> User.count => 2 >> Group.find(:all).map(&:users.map(&:email)) NoMethodError: undefined method `map' for :users:Symbol from (irb):3 >> Group.find(:all).map(&:(users.map(&:email))) SyntaxError: compile error (irb):4: syntax error, unexpected '(', expecting tSTRING_CONTENT or tSTRING_DBEG or tSTRING_DVAR or tSTRING_END Group.find(:all).map(&:(users.map(&:email))) ^ (irb):4: syntax error, unexpected ')', expecting $end Group.find(:all).map(&:(users.map(&:email))) ^ from (irb):4 >> Group.find(:all).map(&:{users.map(&:email)}) SyntaxError: compile error (irb):5: syntax error, unexpected tLBRACE, expecting tSTRING_CONTENT or tSTRING_DBEG or tSTRING_DVAR or tSTRING_END Group.find(:all).map(&:{users.map(&:email)}) ^ (irb):5: odd number list for Hash Group.find(:all).map(&:{users.map(&:email)}) ^ (irb):5: syntax error, unexpected ')', expecting $end from (irb):5 >> Group.find(:all).map(&:"users.map(&:email)") NoMethodError: undefined method `users.map(&:email)' for #<Group:0x1f57a84> from /Users/arie/RealProjects/xxx.com/vendor/rails/activerecord/lib/active_record/attribute_methods.rb:206:in `method_missing' from /Users/arie/RealProjects/xxx.com/vendor/rails/activerecord/lib/../../activesupport/lib/active_support/core_ext/symbol.rb:11:in `__send__' from /Users/arie/RealProjects/xxx.com/vendor/rails/activerecord/lib/../../activesupport/lib/active_support/core_ext/symbol.rb:11:in `to_proc' from (irb):6:in `map' from (irb):6 >> Group.find(:all).map { |g| g.users.map(&:email) } => [["[EMAIL PROTECTED]"]] >> also be careful of def object end duck typing, remember to put it inside parentheses, ex. (def object end).method -- r9 = { name: Rie!, ym: riyari3, skype: rubyninja, li: http://linkedin.com/in/ariekeren, fb: http://profile.to/ariekeren, blog: http://tinyurl.com/2bjgvn } --------------------------------- Never miss a thing. Make Yahoo your homepage. [Non-text portions of this message have been removed]