我有一些经理和足球队模型.一名经理“拥有”许多足球队;经理也可以评论足球队,也可以评论其他经理：

manager.rb

@H_502_4@# Soccer teams the manager owns has_many :soccer_teams,:dependent => :restrict # Comments the manager has made on soccer teams or other managers has_many :reviews,:class_name => "Comment",:foreign_key => :author_id,:dependent => :destroy # Comments the manager has received by other managers has_many :comments,:as => :commentable,:dependent => :destroy # Soccer teams that have received a comment by the manager has_many :observed_teams,:through => :comments,:source => :commentable,:source_type => "SoccerTeam"@H_404_5@

soccer_team.rb

@H_502_4@# The manager that owns the team belongs_to :manager # Comments received by managers has_many :comments,:dependent => :destroy # Managers that have reviewed the team has_many :observers,:source => :author,:class_name => "Manager"@H_404_5@

comment.rb

@H_502_4@belongs_to :commentable,:polymorphic => true belongs_to :author,:class_name => Manager@H_404_5@

现在,如果我有一位经理对SoccerTeam发表评论,我希望找到：

> manager.reviews和soccer_team.comments中的Comment对象
> manager.observed_teams中的SoccerTeam对象
> soccer_team.observers中的Manager对象

虽然一切都适用于第一点和第三点,但当我调用manager.observed_teams时,我总是获得一个空数组.要实际获得经理评论的足球队列表,我需要使用：

@H_502_4@manager.reviews.collect{ |review| Kernel.const_get(review.commentable_type).find(review.commentable_id) if review.commentable_type == "SoccerTeam" }@H_404_5@

这很难看.我希望简单的manager.observed_teams能够工作……为什么不呢？

编辑

我更进一步了解它为什么不起作用.实际上,生成的sql是：

@H_502_4@SELECT "soccer_teams".* FROM "soccer_teams" INNER JOIN "comments" ON "soccer_teams".id = "soccer_teams".commentable_id AND "comments".commentable_type = 'SoccerTeam' WHERE (("comments".commentable_id = 1) AND ("comments".commentable_type = 'Manager'))@H_404_5@

虽然我希望它是：

@H_502_4@SELECT "soccer_teams".* FROM "soccer_teams" INNER JOIN "comments" ON "soccer_teams".id = "comments".commentable_id AND "comments".commentable_type = 'SoccerTeam' WHERE ("comments".author_id = 1)@H_404_5@

所以问题很简单：如何获得该查询？ (启发式尝试：foreign_key ans：正如预期的那样,没有解决问题！).