模型关系 [英] Relationships of model

问题描述

如何获取模型的所有关系.IE，我有 User 模型:

How can I get all relationships for model. IE, I've got User model:

class User < AR::Base
  has_many :messages, :foreign_key => 'author'
  has_many :posts
  belongs_to :role
end

那么我怎么知道User 模型有哪些关系呢?和foreign_keys，如果它们被呈现.

So how can I know which relationships User model has got? And foreign_keys if they are presented.

推荐答案

User.reflect_on_all_associations.each do |assoc|
  puts "#{assoc.macro} #{assoc.name}"
end

输出:

has_many messages
has_many posts
belongs_to role

reflect_on_all_associations 方法返回一个 MacroReflection<的数组/a> 对象.它们也支持其他方法，用于查询每个关联的选项哈希和其他有用的东西.

The reflect_on_all_associations method return an array of MacroReflection objects. They support other methods as well, for querying the options hash of each association and other useful stuff.

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