如何检查Embedded Document中的元素是否为空？ Node.js和Mongodb

Question

I want to check if elements in Embedded Document is empty or not. For example:

if (files.originalFilename === 'photo1.png') {
                user.update(
                    {
                        userName: userName
                    },
                    { $set: { "competitorAnalysisPhoto.photo1" : files.path } }
                );
                console.log('Got photo1!');

                // save the user
                user.save();
            }

Currently, I cannot update the field "photo1" if it is empty. How can I check if it is empty or not?

I try to use:

if (user.competitorAnalysisPhoto.photo1 == null) {
                    console.log('Photo1 is null!');
                    user.competitorAnalysisPhoto.push({
                        photo1: files.path
                    });
                } else {
                    console.log('Photo1 is not null!');
                    user.update(
                        {
                            userName: userName
                        },
                        { $set: { "competitorAnalysisPhoto.photo1" : files.path } }
                    );
                }

However, it is always null no matter photo1 exists or not, printing out "undefined".

Answer 1

Have you tried using 'upsert'?

if (files.originalFilename === 'photo1.png') {
            user.update(
                {
                    userName: userName
                },
                { $set: { "competitorAnalysisPhoto.photo1" : files.path } },
                { upsert: true }
            );
            console.log('Got photo1!');

            // save the user
            user.save();
        }