Question

class Guardian < ActiveRecord::Base
  has_many :patients
  has_one :user, as: :profile
  accepts_nested_attributes_for :user
end


class User < ActiveRecord::Base
  belongs_to :profile, :polymorphic => true

  devise :database_authenticatable, :registerable,
         :recoverable, :rememberable, :trackable, :validatable
end

用户迁移

class DeviseCreateUsers < ActiveRecord::Migration
  def change
    create_table(:users) do |t|
      ## Database authenticatable
      t.string :email,              :null => false, :default => ""
      t.string :encrypted_password, :null => false, :default => ""
      t.string :username, :null => false
      t.string :address
      t.integer :age
      t.string :gender
      t.string :name
      t.integer :profile_id
      t.string :profile_type

      ## Recoverable
      t.string   :reset_password_token
      t.datetime :reset_password_sent_at

      ## Rememberable
      t.datetime :remember_created_at

      ## Trackable
      t.integer  :sign_in_count, :default => 0, :null => false
      t.datetime :current_sign_in_at
      t.datetime :last_sign_in_at
      t.string   :current_sign_in_ip
      t.string   :last_sign_in_ip


      t.timestamps
    end

    add_index :users, :email,                :unique => true
    add_index :users, :reset_password_token, :unique => true
  end
end

class DeviseCreateUsers < ActiveRecord::Migration
  def change
    create_table(:users) do |t|
      ## Database authenticatable
      t.string :email,              :null => false, :default => ""
      t.string :encrypted_password, :null => false, :default => ""
      t.string :username, :null => false
      t.string :address
      t.integer :age
      t.string :gender
      t.string :name
      t.integer :profile_id
      t.string :profile_type

      ## Recoverable
      t.string   :reset_password_token
      t.datetime :reset_password_sent_at

      ## Rememberable
      t.datetime :remember_created_at

      ## Trackable
      t.integer  :sign_in_count, :default => 0, :null => false
      t.datetime :current_sign_in_at
      t.datetime :last_sign_in_at
      t.string   :current_sign_in_ip
      t.string   :last_sign_in_ip
      t.timestamps
    end

    add_index :users, :email,                :unique => true
    add_index :users, :reset_password_token, :unique => true
    end
end

监护人迁移

class CreateGuardians < ActiveRecord::Migration
  def change
    create_table :guardians do |t|
      t.string :family_name

      t.timestamps
    end
  end
end

我想从单个变量中获取用户表和监护人表中的数据监护人有一个用户和用户belongs_to监护人作为简档（多态）。我想从用户表和监护人表中获取数据，其中guardian_id = users.profile_id

Answer 1

尝试

Guardian.select("*").joins(:user)

修改的

如果你可以从联接中获得具有相同名称的列

Guardian.select("guardians.family_name, guardians.id as g_id, users.id as u_id, users.name, users.email, users.username, users.address, users.age, users.gender").joins(:user).where(:users => {:u_id => @user_session.id})

Answer 2

由于某些原因，上述答案对我没有用，所以我尝试直接sql查询

sqlQuery = "select tableA.column1, tableB.column2 from tableA inner join tableB on tableA.some_id = tableB.id"
ActiveRecord::Base.connection.execute(sqlQuery)

连接两个表来获取数据轨道4

2 个答案: