Ruby on Rails的：有关的问题validates_ presence_of [英] Ruby on Rails: question about validates_presence_of

问题描述

我有一个看起来像我的ActiveRecord基于模型的关系：

I have a relationship in my ActiveRecord based model that looks like:

belongs_to :foo

我的模型应该始终有它的定义FOO它是有效的。我的问题是，使用validates_ $ P $的psence时，哪一个是一个合适的使用方法：

My model should always have foo defined in it for it to be valid. My question is, when using validates_presence of, which one is the appropriate one to use:

validates_presence_of :foo

或

validates_presence_of :foo_id

这里假设当然，这foo_id是相应的外键，它在默认情况下，如果你不改变的关联键。

Assuming here of course, that foo_id is the appropriate foreign key, which it is by default if you do not change the association key.

推荐答案

第一个： validates_ presence_of：富（虽然我认为第二个将工作太）。在一般的红宝石验证辅助型号名称的工作，而不是明确的列名。您可以使用此的除了的 validates_associated 这两个验证它除了presence相关实体的状态。

The first one: validates_presence_of :foo (though I think the second one will work too). In general the Ruby validation helpers work on model names as opposed to explicit column names. You can use this in addition to validates_associated to both validate the state of the associated entity in addition to its presence.

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