How to Update Multiple Array Elements in mongodb

How to Update Multiple Array Elements in MongoDB

Updating multiple array elements in MongoDB can be a tricky task, but fear not! In this blog post, we will tackle this common issue and provide you with easy solutions. 🚀

The Problem

Let's begin by understanding the problem at hand. You have a MongoDB document that contains an array of elements. You want to update the .handled attribute of all objects in the array where the .profile value is equal to XX.

Here is an example of your MongoDB document:

{
    "_id": ObjectId("4d2d8deff4e6c1d71fc29a07"),
    "user_id": "714638ba-2e08-2168-2b99-00002f3d43c0",
    "events": [
        {
            "handled": 1,
            "profile": 10,
            "data": "....."
        },
        {
            "handled": 1,
            "profile": 10,
            "data": "....."
        },
        {
            "handled": 1,
            "profile": 20,
            "data": "....."
        },
        ...
    ]
}

The Solution

Your initial attempt to update the array elements using the positional operator ($) is close, but it only updates the first matched array element in each document. To update all matched array elements, we can use a combination of the $[] operator and the $[identifier] operator.

The $[] operator acts as a placeholder, allowing us to update all array elements, while the $[identifier] operator filters the elements that need to be updated based on a condition.

Here's how you can achieve it:

db.collection.update({ "events.profile": 10 }, { $set: { "events.$[].handled": 0 } });

In the above query, we use the $[identifier] operator to specify the condition {"events.profile": 10} and update the handled attribute to 0 for all matching array elements using "events.$[].handled".

Conclusion

Updating multiple array elements in MongoDB can be done efficiently using the $[] and $[identifier] operators. With these solutions at your disposal, you can confidently update array elements with ease.

If you have any questions or face any challenges, feel free to leave a comment below. Happy coding! 💻

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