轨道上的红宝石 - 活动记录：：记录无效(验证失败：Word 不能为空)

Question

给定以下代码:

class Word < ActiveRecord::Base
  has_and_belongs_to_many :definitions
end
class Definition < ActiveRecord::Base
  has_and_belongs_to_many :word
  validates :word, presence: true
end
mysql> show columns from definitions_words;
+---------------+---------+------+-----+---------+-------+
| Field         | Type    | Null | Key | Default | Extra |
+---------------+---------+------+-----+---------+-------+
| definition_id | int(11) | NO   | PRI | NULL    |       |
| word_id       | int(11) | NO   | PRI | NULL    |       |
+---------------+---------+------+-----+---------+-------+

当我打电话时:

word = Word.first
word.definitions.create!

我

:

ActiveRecord::RecordInvalid (Validation failed: Word can't be blank)

Answer 1

First:您对定义类的关系是错误的。应该是复数!:单词

秒:验证也是错误的。它也应该是复数形式。例如验证:words

通过这种方式，它期望带有name word的字段不是空的，而不是关系。

尝试将示例代码更改为:

word = Word.first
definition = Definition.new
definition.words = [word]
definition.save