如何在mongo中使用.save方法

Question

 app.put('/app/modify/:_id', function(req, res) {
        Collection.findById(req.params._id, function (err, blog) {
            if (err) res.send(err);
            if (req.body.text1) blog.text1 = req.body.text1;
            if (req.body.text2) blog.text2 = req.body.text2;
            if (req.body.text3) blog.text3 = req.body.text3;
            if (req.body.text4) blog.text4 = req.body.text4;
            if (req.body.text5) blog.text5 = req.body.text5;
            Collection.save( function (err) {
                if (err) send (err);
                res.json({message: 'Blog Post Updated!'});
            });
        });
    });

从此获得帮助 - 放置和删除 - Restful Api Express MongoDB Mongoose

但获取错误 - http：//localhost：8080/app/modify/59203c7d9532c34903000002 net :: err_empty_response和Node Server and Node Server and error'Collection'Collection'Collection'Collection'Collection'Collection'Collection.Save save not功能'。

尝试...

 app.put('/app/modify/:_id', function(req, res) {
            Collection.findById(req.params._id, function (err, blog) {
                if (err) res.send(err);
                if (req.body.text1) blog.text1 = req.body.text1;
                if (req.body.text2) blog.text2 = req.body.text2;
                if (req.body.text3) blog.text3 = req.body.text3;
                if (req.body.text4) blog.text4 = req.body.text4;
                if (req.body.text5) blog.text5 = req.body.text5;
                blog.save( function (err,response) {
                    if (err) res.json(err);
                    res.json({message: 'Blog Post Updated!'});
                });
            });
        });