belongs_to를 사용할 때 모델을 결합 할 수 없음

Question

class Exercise < ActiveRecord::Base 
    belongs_to :user 
end 

class User < ActiveRecord::Base 
    has_many :exercises 
end 

"Admin"역할을 가진 사용자가 만든 모든 연습을 찾을 수없는 이유는 무엇입니까?

Exercise.first :include => [:user], :conditions => ['user.role = "admin"'] 

사용자 테이블이 연결되지 않는 오류가 발생합니다.

Exercise.first :include => [:user], :conditions => ['user.role = "admin"'] 
    Exercise Load Including Associations (0.0ms) Mysql::Error: Unknown column 'user.role' in 'where clause': SELECT `exercises`.`id` AS t0_r0, `exercises`.`title` AS t0_r1, `exercises`.`description` AS t0_r2, `exercises`.`fitness_type` AS t0_r3, `exercises`.`trackables` AS t0_r4, `exercises`.`user_id` AS t0_r5, `exercises`.`created_at` AS t0_r6, `exercises`.`updated_at` AS t0_r7, `users`.`id` AS t1_r0, `users`.`created_at` AS t1_r1, `users`.`updated_at` AS t1_r2, `users`.`first_name` AS t1_r3, `users`.`last_name` AS t1_r4, `users`.`email` AS t1_r5, `users`.`crypted_password` AS t1_r6, `users`.`password_salt` AS t1_r7, `users`.`persistence_token` AS t1_r8, `users`.`single_access_token` AS t1_r9, `users`.`perishable_token` AS t1_r10, `users`.`login_count` AS t1_r11, `users`.`failed_login_count` AS t1_r12, `users`.`last_request_at` AS t1_r13, `users`.`current_login_at` AS t1_r14, `users`.`last_login_at` AS t1_r15, `users`.`current_login_ip` AS t1_r16, `users`.`last_login_ip` AS t1_r17, `users`.`role` AS t1_r18, `users`.`avatar_file_name` AS t1_r19, `users`.`avatar_content_type` AS t1_r20, `users`.`avatar_file_size` AS t1_r21, `users`.`avatar_updated_at` AS t1_r22 FROM `exercises` LEFT OUTER JOIN `users` ON `users`.id = `exercises`.user_id WHERE (user.role = "admin") LIMIT 1 
ActiveRecord::StatementInvalid: Mysql::Error: Unknown column 'user.role' in 'where clause': SELECT `exercises`.`id` AS t0_r0, `exercises`.`title` AS t0_r1, `exercises`.`description` AS t0_r2, `exercises`.`fitness_type` AS t0_r3, `exercises`.`trackables` AS t0_r4, `exercises`.`user_id` AS t0_r5, `exercises`.`created_at` AS t0_r6, `exercises`.`updated_at` AS t0_r7, `users`.`id` AS t1_r0, `users`.`created_at` AS t1_r1, `users`.`updated_at` AS t1_r2, `users`.`first_name` AS t1_r3, `users`.`last_name` AS t1_r4, `users`.`email` AS t1_r5, `users`.`crypted_password` AS t1_r6, `users`.`password_salt` AS t1_r7, `users`.`persistence_token` AS t1_r8, `users`.`single_access_token` AS t1_r9, `users`.`perishable_token` AS t1_r10, `users`.`login_count` AS t1_r11, `users`.`failed_login_count` AS t1_r12, `users`.`last_request_at` AS t1_r13, `users`.`current_login_at` AS t1_r14, `users`.`last_login_at` AS t1_r15, `users`.`current_login_ip` AS t1_r16, `users`.`last_login_ip` AS t1_r17, `users`.`role` AS t1_r18, `users`.`avatar_file_name` AS t1_r19, `users`.`avatar_content_type` AS t1_r20, `users`.`avatar_file_size` AS t1_r21, `users`.`avatar_updated_at` AS t1_r22 FROM `exercises` LEFT OUTER JOIN `users` ON `users`.id = `exercises`.user_id WHERE (user.role = "admin") LIMIT 1 
    from /Library/Ruby/Gems/1.8/gems/activerecord-2.3.5/lib/active_record/connection_adapters/abstract_adapter.rb:219:in `log' 
    from /Library/Ruby/Gems/1.8/gems/activerecord-2.3.5/lib/active_record/connection_adapters/mysql_adapter.rb:323:in `execute' 
    from /Library/Ruby/Gems/1.8/gems/activerecord-2.3.5/lib/active_record/connection_adapters/mysql_adapter.rb:608:in `select' 
    from /Library/Ruby/Gems/1.8/gems/activerecord-2.3.5/lib/active_record/connection_adapters/abstract/database_statements.rb:7:in `select_all_without_query_cache' 
    from /Library/Ruby/Gems/1.8/gems/activerecord-2.3.5/lib/active_record/connection_adapters/abstract/query_cache.rb:62:in `select_all' 
    from /Library/Ruby/Gems/1.8/gems/activerecord-2.3.5/lib/active_record/associations.rb:1617:in `select_all_rows' 
    from /Library/Ruby/Gems/1.8/gems/activerecord-2.3.5/lib/active_record/associations.rb:1395:in `find_with_associations' 
    from /Library/Ruby/Gems/1.8/gems/activerecord-2.3.5/lib/active_record/associations.rb:1393:in `catch' 
    from /Library/Ruby/Gems/1.8/gems/activerecord-2.3.5/lib/active_record/associations.rb:1393:in `find_with_associations' 
    from /Library/Ruby/Gems/1.8/gems/activerecord-2.3.5/lib/active_record/base.rb:1546:in `find_every' 
    from /Library/Ruby/Gems/1.8/gems/activerecord-2.3.5/lib/active_record/base.rb:1505:in `find_initial' 
    from /Library/Ruby/Gems/1.8/gems/activerecord-2.3.5/lib/active_record/base.rb:613:in `find' 
    from /Library/Ruby/Gems/1.8/gems/activerecord-2.3.5/lib/active_record/base.rb:623:in `first' 
    from (irb):7 
>> 

은 내가 먼저 관리자 사용자가 다음 "USER_ID"에 의해 운동을 찾아 찾아 2 단계 과정에서이 작업을 수행 할 수 있습니다 알고 있지만 named_scope에이를 만들고 싶어.

Answer 1

을 나는 그것이

Exercise.first :include => [:user], :conditions => ['users.role = "admin"'] 

대신

Exercise.first :include => [:user], :conditions => ['user.role = "admin"'] 

입니다 확신

Answer 2

귀하의 조건은 복수로 사용자가 있어야합니다 users.role