Question

我有3个表：users，meeting_types和user_meeting_types

现在我想在users表格上应用查询并在user_meeting type中传递条件

User有很多会议，会议有一个meeting_type

如何在user和user_meeting_type上应用条件并从所有表中获取数据？

我想要所有表格中的数据

查询是这样的：

Select * from users left join user_meeting_types on user.id = user_meeting_types.user_id left join meeting_types on user_meeting_types.meeting_id = meeting_type.id where user.id = 37 and user_meeting_type.meeting_id = 5

user.rb

class User
  has_many :UserMeetingType

user_meeting_type.rb

class UserMeetingType
  belongs_to :UserMeeting

Answer 1

模型如下：

class User < ActiveRecord::Base
   has_many :user_meeting_types
end

class MeetingType < ActiveRecord::Base
end

class UserMeetingType < ActiveRecord::Base
   belongs_to :meeting_type
end

首先，您必须获取用户：

user = User.find(37) # Select * from users where id = 37

然后恢复特定用户user_meeting_types

meetings = user.user_meeting_types.where(meeting_type_id:7) #Select * from user_meeting_types where user_id = 37 and meeting_type_id = 7

在rails中应用条件hasMany

1 个答案: