Node.js Mongoose无法读取具有复杂架构的未定义属性

我有以下用户模式：

var mongoose = require('mongoose');
var userSchema = mongoose.Schema({
    local: {
         email: String,
         password: String
    },
    education: {
        school: {
            start: Boolean,
            name: String,
            graduationYear: String
        },
        college: {
            start: Boolean,
            name: String,
            career: String,
            enterYear: String,
            graduationYear: String
        }
    }
});

现在，当我提交包含所有这些信息的表单时，我的应用程序会将POST请求路由到以下功能：

exports.postEditEducation = function (req, res){
    process.nextTick(function (){
        var user = req.user;

        user.education.school.start = req.body.schoolStart;
        user.education.school.name = req.body.schoolName;
        user.education.school.graduationYear = req.body.graduationYear;

        user.education.college.start = req.body.collegeStart;
        user.education.college.name = req.body.collegeName;
        user.education.college.career = req.body.collegeCareer;
        user.education.college.enterYear = req.body.collegeEnterYear;
        user.education.college.graduationYear = req.body.collegeGraduationYear;

        user.save(function (err){
            if (err)
                throw err;

            res.redirect('/profile');
        });
    });
};

但是，当我提交信息时，出现以下错误：

user.education.college.start = req.body.collegeStart;
                             ^
TypeError: Cannot set property 'start' of undefined
    at /file.js:464:46
    at process._tickCallback (node.js:419:13)

您已经为保存req.user创建了变量

 user.education.college.start 

为此，应创建一个用户集合实例。为userschema创建一些实例。 例如，我假设userschema的集合名称为usercollection：

var userobj = new usercollection(); 
userobj.education.college.start = req.body.schoolStart; ..

---

希望这可能有用。

实际上，这对我没有任何帮助，因为我使用passport对用户进行身份验证，因此我可以使用req.user从请求中检索用户。我的问题是我可以设置所有的学校属性，但不能设置大学属性

var userobj = new usercollection(); 
userobj.education.college.start = req.body.schoolStart; ..