我有用户和角色表，它们有多对多关联。我的数据库有users，roles和role_users表。基本上我想在role_users表中保存用户的角色，这基本上是用户和角色的连接表。我从角色表中获取用户页面上的user'role，并希望将它们保存在role_users表中。但是我无法在role_users表中保存用户角色。我在用户的“创建控制器”中编写了代码，以便在role_users表中保存数据但是没有发生。
users_controller.rb
class Admin::UsersController < Admin::BaseController
before_filter :find_user, :only => [:show, :edit, :update, :destroy]
def index
@users = User.all( :order => :email )
@roles = Role.all
end
def show
end
def new
@user = User.new
end
def create
is_admin = params[:user].delete(:is_admin) == "1"
@user = User.new(params[:user])
**@user_role = RoleUser.new({:user_id => @user.id, :role_id => params[:role_user]})**
#@user_role.role_id = params[:role_id]
#@user_role.user_id = current_user.id
@user_role.save
@user.is_admin = is_admin
if @user.save
flash[:notice] = "User has been created."
redirect_to admin_users_path
else
flash[:alert] = "User has not been created."
render :action => :new
end
end
def edit
end
def update
if params[:user][:password].empty?
params[:user].delete(:password)
end
set_admin
if @user.update_attributes(params[:user])
flash[:notice] = "User has been updated."
redirect_to admin_users_path
else
flash[:alert] = "User has not been updated."
render :action => :new
end
end
def destroy
if @user == current_user
flash[:alert] = "You cannot delete yourself!"
else
@user.destroy
flash[:notice] = "User has been deleted."
end
redirect_to admin_users_path
end
private
def find_user
@user = User.find(params[:id])
end
def set_admin
is_admin = params[:user].delete(:is_admin) == "1"
@user.is_admin = true
end
end
schema.rb
# encoding: UTF-8
# This file is auto-generated from the current state of the database. Instead
# of editing this file, please use the migrations feature of Active Record to
# incrementally modify your database, and then regenerate this schema definition.
#
# Note that this schema.rb definition is the authoritative source for your
# database schema. If you need to create the application database on another
# system, you should be using db:schema:load, not running all the migrations
# from scratch. The latter is a flawed and unsustainable approach (the more migrations
# you'll amass, the slower it'll run and the greater likelihood for issues).
#
# It's strongly recommended to check this file into your version control system.
ActiveRecord::Schema.define(:version => 20130601093644) do
create_table "role_users", :force => true do |t|
t.integer "role_id"
t.integer "user_id"
t.datetime "created_at", :null => false
t.datetime "updated_at", :null => false
end
create_table "roles", :force => true do |t|
t.string "name"
t.datetime "created_at", :null => false
t.datetime "updated_at", :null => false
end
create_table "team_users", :force => true do |t|
t.integer "team_id"
t.integer "user_id"
t.integer "team_lead_id"
t.datetime "created_at", :null => false
t.datetime "updated_at", :null => false
end
create_table "teams", :force => true do |t|
t.string "name"
t.datetime "created_at", :null => false
t.datetime "updated_at", :null => false
t.integer "team_lead_id"
end
create_table "users", :force => true do |t|
t.string "email", :default => "", :null => false
t.string "encrypted_password", :default => "", :null => false
t.string "reset_password_token"
t.datetime "reset_password_sent_at"
t.datetime "remember_created_at"
t.integer "sign_in_count", :default => 0
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.datetime "created_at", :null => false
t.datetime "updated_at", :null => false
t.boolean "is_admin"
t.string "username"
t.string "first_name"
t.string "last_name"
t.string "contact_no"
t.date "birth_date"
t.boolean "is_active"
t.date "joining_date"
t.string "avatar_url"
t.boolean "is_hr"
t.boolean "is_manager"
t.string "designation"
t.string "user_code"
t.string "user_role"
end
add_index "users", ["email"], :name => "index_users_on_email", :unique => true
add_index "users", ["reset_password_token"], :name => "index_users_on_reset_password_token", :unique => true
end
_form.html.erb（用于创建新用户）
<div style="margin-left:200px">
<%= form_for [:admin, @user] do |f| %>
<% @user.errors.full_messages.each do |msg| %>
<li><%= msg %></li>
<% end %>
<div style=" margin-top:10px">
<%= f.label :first_name, :class => 'control-label' %>
<div class="">
<%= f.text_field :first_name, :class => 'text_field' %>
</div>
</div>
<div style="margin-left:350px; margin-top:-65px">
<%= f.label :last_name, :class => 'control-label' %>
<div class="">
<%= f.text_field :last_name, :class => 'text_field' %>
</div>
</div>
<div style=" margin-top:10px">
<%= f.label :user_code, :class => 'control-label' %>
<div class="">
<%= f.text_field :user_code, :class => 'text_field' %>
</div>
</div>
<div style="margin-left:350px; margin-top:-65px">
<%= f.label :email, :class => 'control-label' %>
<div class="">
<%= f.text_field :email, :class => 'text_field' %>
</div>
</div>
<div style=" margin-top:10px">
<%= f.label :contact_no, :class => 'control-label' %>
<div class="">
<%= f.text_field :contact_no, :class => 'text_field' %>
</div>
</div>
<div style="margin-left:350px; margin-top:-65px">
<%= f.label :birth_date, :class => 'control-label' %>
<div class="">
<%= f.text_field :birth_date, :class => 'datepicker ' %>
</div>
</div>
<div style=" margin-top:10px">
<%= f.label :joining_date, :class => 'control-label' %>
<div class="">
<%= f.text_field :joining_date, :class => 'datepicker ' %>
</div>
</div>
<div style="margin-left:350px; margin-top:-65px">
<%= f.label :password, :class => 'control-label' %>
<div class="">
<%= f.password_field :password, :class => 'password-field' %>
</div>
</div>
<div style="margin-left:0px; margin-top:00px">
<%= f.label :designation , :class => 'control-label' %>
<select name="user[designation]">
<option value="">Please select</option>
<option value="Administrator">Administrator</option>
<option value="User">Trainee</option>
<option value="Software Engineer">Software Engineer</option>
<option value="Senior Software Engineer">Senior Software Engineer</option>
<option value="Quality Engineer">Quality Engineer</option>
<option value="Team Lead">Team Lead</option>
</select>
</div>
<label> User Role</label>
<%= select_tag "role_id", options_from_collection_for_select( Role.all, "id", "name"), :style => "width:270px; height:35px" %>
<div style="margin-top:20px">
<%= f.check_box :is_active %>
<div class="">
<%= f.label :is_active, "Is an active user?", :class => 'control-label' %>
</div>
</div>
<div style="margin-left:190px; margin-top:-35px">
<%= f.check_box :is_admin %>
<div class="">
<%= f.label :is_admin, "Is an admin?", :class => 'control-label' %>
</div>
</div>
<div style="margin-left:00px; margin-top:15px">
<%= f.check_box :is_hr %>
<div class="">
<%= f.label :is_hr, "Is hr?", :class => 'control-label' %>
</div>
</div>
<div style="margin-left:190px; margin-top:-35px">
<%= f.check_box :is_manager %>
<div class="">
<%= f.label :is_manager, "Is Manager?", :class => 'control-label' %>
</div>
</div>
<div style="margin-left:00px; margin-top:30px">
<%= f.submit :class => 'btn btn-primary' %>
<div style="margin-left:130px;margin-top:-32px">
<%= link_to t('.back', :default => t("helpers.links.back")),
admin_users_path, :class => 'btn' %>
</div>
</div>
<% end %>
</div>
user.rb
class User < ActiveRecord::Base
has_many :roles, through: :role_users
has_many :role_users
# Include default devise modules. Others available are:
# :token_authenticatable, :confirmable,
# :lockable, :timeoutable and :omniauthable
devise :database_authenticatable, :registerable,
:recoverable, :rememberable, :trackable, :validatable
# Setup accessible (or protected) attributes for your model
attr_accessible :username, :email, :password, :password_confirmation,
:remember_me, :first_name, :last_name, :is_admin, :contact_no, :birth_date,
:joining_date, :is_active, :is_hr, :is_manager, :user_code, :designation
# attr_accessible :title, :body
end
role_user.rb
class RoleUser < ActiveRecord::Base
belongs_to :user
belongs_to :role
attr_accessible :role_id, :user_id
end
role.rb
class Role < ActiveRecord::Base
attr_accessible :name
has_many :users, through: :role_users
has_many :role_users
end
简而言之，我想在role_users表中保存user'role，这是用户和角色的连接表。为此，我在 users_controller.rb
中编写了以下代码@user_role = RoleUser.new({:user_id => @user.id, :role_id => params[:role_user]})
但是，数据不会保存在db。
中答案 0 :(得分：1)
在您创建RoleUser时，您的User个实例中还没有ID。
def create
is_admin = params[:user].delete(:is_admin) == "1"
@user = User.new(params[:user])
# @user is not saved here and has no id
**@user_role = RoleUser.new({:user_id => @user.id, :role_id => params[:role_user]})**
@user_role.save
# based on your validations, it's likely that this @user_role.save is returning false
在有星星的行上，@ user已经构建但未保存。保存RoleUser后尝试构建User个实例。
尝试在此行之后保存RoleUser：if @user.save