Question

我的rails应用程序中有多个模型

class SnapshotReport < ActiveRecord::Base
  establish_connection "evercam_db_#{Rails.env}".to_sym

  belongs_to :camera

  def self.add_report
    camera_report = Snapshot.connection.select_all("select camera_id,count(*) as snapshot_count from snapshots where created_at in (select created_at from snapshots where created_at >= 'now'::date - 1 and  created_at >= 'now'::date - 1) group by camera_id").to_hash

    camera_report.each do |camera|
        SnapshotReport.create(camera_id: camera["camera_id"], snapshot_count: camera["snapshot_count"], report_date: Date.yesterday)
    end
  end
end

并且还有两个相机和用户模型，我正在获取具有日期SnapshotReport.find_by_report_date("01/19/2016")的snapshot_report，但将其保存到@report，我想在视图中显示来自用户和相机的一些数据比如

user = who is owner of the camera
exid = which is of camera

上述查询的结果是

#<SnapshotReport id: 40, camera_id: 5992, created_at: "2016-01-20 08:25:11", report_date: "2016-01-19 00:00:00", snapshot_count: 345>

我的其他协会是

class Camera < ActiveRecord::Base
  establish_connection "evercam_db_#{Rails.env}".to_sym

  belongs_to :user, :foreign_key => 'owner_id', :class_name => 'EvercamUser'
  belongs_to :vendor_model, :foreign_key => 'model_id', :class_name => 'VendorModel'
  has_many :camera_shares, dependent: :delete_all
  has_many :snapshot_report, foreign_key: "camera_id", class_name: "SnapshotReport"

用户

class EvercamUser < ActiveRecord::Base
  establish_connection "evercam_db_#{Rails.env}".to_sym

  self.table_name = "users"
  belongs_to :country
  has_many :cameras, :foreign_key => 'owner_id', :class_name => 'Camera'
  has_many :snapshots
  has_many :vendors
  has_many :camera_shares, :foreign_key => 'user_id', :class_name => 'CameraShare'

Answer 1

您可以通过关联获取用户和相机信息。

user = @report.camera.user
exid = @report.camera.exid

rails关联来检索记录

1 个答案: