如何加入这个表？
我是 Rails 新手
错误
Mysql2::Error: Unknown column 'states.ad_id' in 'where clause': SELECT `states`.* FROM `states` WHERE (`states`.ad_id = 1) LIMIT 1
我的模型
ad.rb
has_one :state
state.rb
belongs_to :ad
这是我的表格。
广告表格
+----+----------------+-------------+-------+-----------+
| id | title | description | price | states_id |
+----+----------------+-------------+-------+-----------+
| 1 | ebook | asdasd | 1 | 1 |
| 2 | iphone 4 devol | sdfsdf | 1 | 1 |
| 3 | asd | asd | 1 | 2 |
+----+----------------+-------------+-------+-----------+
状态表
+----+----------+
| id | name |
+----+----------+
| 1 | Pluto |
| 2 | Mars |
+----+----------+
im new to rails
error
Mysql2::Error: Unknown column 'states.ad_id' in 'where clause': SELECT `states`.* FROM `states` WHERE (`states`.ad_id = 1) LIMIT 1
my model
ad.rb
has_one :state
state.rb
belongs_to :ad
here are my tables.
ads table
+----+----------------+-------------+-------+-----------+
| id | title | description | price | states_id |
+----+----------------+-------------+-------+-----------+
| 1 | ebook | asdasd | 1 | 1 |
| 2 | iphone 4 devol | sdfsdf | 1 | 1 |
| 3 | asd | asd | 1 | 2 |
+----+----------------+-------------+-------+-----------+
states table
+----+----------+
| id | name |
+----+----------+
| 1 | Pluto |
| 2 | Mars |
+----+----------+
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评论（2）
您的错误消息告诉您 states 表中没有 ad_id 列。
您可能想使用 states.id 而不是 states.ad_id
Your error message tells you that you dont have ad_id column in the states table.
You probably wanted to use states.id instead of states.ad_id
请参阅它是属于还是属于关联？ http://api.rubyonrails.org/classes/ActiveRecord/Associations/ClassMethods 部分.html
在您的示例中，您可能希望
状态
has_many :ads广告
belongs_to :state如下指定多对一关系而不是一对一关系，因为一个州可以有许多广告
see the Is it a belongs_to or has_one association? section of http://api.rubyonrails.org/classes/ActiveRecord/Associations/ClassMethods.html
in your example you probably want
state
has_many :adsad
belongs_to :stateas you are specifying a many to one as opposed to a one to one relationship, since a state can have many ads