Include all existing fields and add new fields to document

🖥️📄🔤 Tech Blog: How to easily include all existing fields and add new fields to your document without listing each field separately! ⚡️

Are you tired of manually listing every single field in your document when you want to add new fields? 😩 Well, you're in luck because I have a simple solution for you! 🎉

In this blog post, we will address the common issue of including all existing fields and adding new fields to your document without the hassle of listing each field individually. 💪💻

Let's dive right into the problem at hand. 🏊‍♀️

The Problem:

You have a document with a large number of fields, and you want to create an aggregation stage where you can add a new field while including all the existing fields. However, you don't want to go through the tedious task of listing each field separately. 📋😫

Here's an example of what your document might look like:

{
    obj: {
        obj_field1: "hi",
        obj_field2: "hi2"
    },
    field1: "a",
    field2: "b",
    ...
    field26: "z"
}

Now, let's look at the aggregation operation you want to perform:

[
    {
        $project: {
            custom_field: "$obj.obj_field1",
            // Is there a way to avoid listing each field?
            field1: 1,
            field2: 1,
            ...
            field26: 1
        }
    },
    ... // additional stages
]

You're wondering if there's a keyword or some other way to avoid the manual listing of each field. 🤔

The Solution:

Fortunately, MongoDB provides a solution for this exact problem! 🙌🎉

Instead of listing each field separately, you can use the $getField operator in conjunction with the $mergeObjects operator. This allows you to easily include all existing fields while adding new fields to your document. 🚀

Here's an updated version of your aggregation operation using the $getField operator:

[
    {
        $project: {
            custom_field: "$obj.obj_field1",
            all_fields: { $mergeObjects: "$$ROOT" }
        }
    },
    ... // additional stages
]

In this example, we added a new field called all_fields which includes all the existing fields. 📝💼

The Call-to-Action:

Now that you have an easy solution to include all existing fields and add new fields to your document, why not give it a try? ✨

Try implementing the $getField and $mergeObjects operators in your own code and see how it simplifies your aggregation operations. Don't forget to share your experience in the comments below! 👇

If you found this blog post helpful, please share it with your friends and colleagues who might be facing the same issue. Let's spread the knowledge and make MongoDB aggregation operations a breeze! 💫

Happy coding! 💻🌈