我的两个模型用户和提交如下：
class User < ActiveRecord::Base
# Associations
has_many :submissions
accepts_nested_attributes_for :submissions
# Setup accessible (or protected) attributes for your model
attr_accessible :email,:name,:role,:submission_ids,:quotation_ids,:submissions_attributes
validates :email,:presence => {:message => "Please enter a valid email address" }
validates :email,:uniqueness => { :case_sensitive => false }
end
class Submission < ActiveRecord::Base
belongs_to :user
attr_accessible :due_date,:text,:title,:word_count,:work_type,:rush,:user,:notes
validates :work_type,:presence => true
validates :text,:length => { :minimum => 250 }
validates :word_count,:numericality => { :only_integer => true }
end
我有一个表格收集这两个模型所需的数据.用户控制器：
def index
@user = User.new
@user.submissions.build
end
def create
@user = User.where(:email => params[:user][:email]).first_or_create(params[:user])
if @user
redirect_to :root
else
render 'pages/index'
end
end
我想要做的是首先通过提交的电子邮件检查用户是否已经存在于系统中.如果是,那么我想为该用户创建提交.否则,请同时创建用户和提交.
我对如何使用first_or_create方法执行此操作感到困惑.
任何帮助赞赏.
解决方法
first_or_create
accepts a block.所以你可以这样做：
@user = User.where(:email => params[:user][:email]).first_or_create do |user| # This block is called with a new user object with only :email set # Customize this object to your will user.attributes = params[:user] # After this,first_or_create will call user.create,so you don't have to end