Ruby-on-rails rails 中的 t.belongs_to 和 t.references 有什么区别？
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What is the difference between t.belongs_to and t.references in rails?
提问by Tornskaden
What is the difference between t.referencesand t.belongs_to?
Why are we having those two different words? It seems to me they do the same thing?
Tried some Google search, but find no explanation.
t.references和 和有t.belongs_to什么区别？为什么我们有这两个不同的词？在我看来他们做同样的事情？尝试了一些谷歌搜索，但没有找到任何解释。
class CreateFoos < ActiveRecord::Migration
def change
create_table :foos do |t|
t.references :bar
t.belongs_to :baz
# The two above seems to give similar results
t.belongs_to :fooable, :polymorphic => true
# I have not tried polymorphic with t.references
t.timestamps
end
end
end
回答by muffinista
Looking at the source code, they do the same exact thing -- belongs_tois an alias of reference:
查看源代码，他们做同样的事情——belongs_to是一个别名reference：
def references(*args)
options = args.extract_options!
polymorphic = options.delete(:polymorphic)
args.each do |col|
column("#{col}_id", :integer, options)
column("#{col}_type", :string, polymorphic.is_a?(Hash) ? polymorphic : options) unless polymorphic.nil?
end
end
alias :belongs_to :references
This is just a way of making your code more readable -- it's nice to be able to put belongs_toin your migrations when appropriate, and stick to referencesfor other sorts of associations.
这只是使您的代码更具可读性的一种方式——能够belongs_to在适当的时候进行迁移并坚持references其他类型的关联是很好的。
