1.extend调用的时候返回值有问题

使用方案1的时候，extend返回的结果，movie,_movie值都不对

改用方案2的时候，返回的结果_movie与movieObj一样，都是json结构的值

app.post('/admin/movie/new', function(req, res){
    var id = req.body.movie._id
    var movieObj = req.body.movie
    var _movie

    if(id !== 'undefined'){
        Movie.findById(id, function(err, movie){
            if(err){
                console.log(err)
            }
            //_movie = new Movie()
            console.log('movie')
            console.log(movie)
            console.log('_movie')
            console.log(_movie)
            _movie = _.extend(movie, movieObj)  //方案1
            _movie = _.extend({}, movieObj)    //方案2
            console.log('movieobj')
            console.log(movieObj)
            console.log('movie')
            console.log(movie)
            console.log('_movie')
            console.log(_movie)
            _movie.save(function(err, movie){
                if(err){
                    console.log(err)
                }

                res.redirect('/movie/' + movie._id)
            })
        })
    }
    else{
        _movie = new Movie({
            director: movieObj.director,
            title: movieObj.title,
            country: movieObj.country,
            language: movieObj.language,
            year: movieObj.year,
            poster: movieObj.poster,
            summary: movieObj.summary,
            flash: movieObj.flash
        })

        _movie.save(function(err, movie){
            if(err){
                console.log(err)
            }
            res.redirect('/movie/' + movie._id)
        })
    }
})

2.采用方案2之后，调用的save方法有问题

imooc started on port 3000
movie
null
_movie
undefined
movieobj
{ title: '机械战警007',
  director: '若泽·帕迪里亚',
  country: 'America',
  language: 'English',
  poster: 'http://img5.douban.com/view/movie_poster_cover/spst/public/p2170735207.jpg',
  flash: 'http://player.youku.com/player.php/sid/XNjMyMTkzODcy/v.swf',
  year: '2014',
  summary: 'gggggggggggggggggggggggggggggggggggggggggggg' }
movie
null
_movie
{ title: '机械战警007',
  director: '若泽·帕迪里亚',
  country: 'America',
  language: 'English',
  poster: 'http://img5.douban.com/view/movie_poster_cover/spst/public/p2170735207.jpg',
  flash: 'http://player.youku.com/player.php/sid/XNjMyMTkzODcy/v.swf',
  year: '2014',
  summary: 'gggggggggggggggggggggggggggggggggggggggggggg' }

/home/lee/imooc/app.js:98
            _movie.save(function(err, movie){
                   ^
TypeError: Object #<Object> has no method 'save'