How to update array with multiple conditions in MongoDB

To update array with multiple conditions in MongoDB, use $elemMatch to match array elements with specific criteria, combined with $push and the positional operator $ to add new elements to the matched array element.

Syntax

db.collection.updateOne(
    { "arrayField": { "$elemMatch": { "field1": "value1", "field2": "value2" } } },
    { "$push": { "arrayField.$.targetField": newValue } }
);

Sample Data

db.demo94.insertOne({
    "Details": [
        {
            "Name": "Chris",
            "Subject": []
        },
        {
            "Name": "David", 
            "Subject": []
        },
        {
            "Name": "Bob",
            "Subject": []
        }
    ]
});

{
    "acknowledged": true,
    "insertedId": ObjectId("5e2d553bb8903cdd865577a9")
}

Example: Update Array Element with Multiple Conditions

Add a subject to David's Subject array using $elemMatch to locate the specific array element ?

db.demo94.updateOne(
    {
        "Details": { "$elemMatch": { "Name": "David" } }
    },
    {
        "$push": { "Details.$.Subject": { "Subject": "MongoDB" } }
    }
);

{ "acknowledged": true, "matchedCount": 1, "modifiedCount": 1 }

Verify Result

db.demo94.find();

{
    "_id": ObjectId("5e2d553bb8903cdd865577a9"), 
    "Details": [
        { "Name": "Chris", "Subject": [] },
        { "Name": "David", "Subject": [{ "Subject": "MongoDB" }] },
        { "Name": "Bob", "Subject": [] }
    ]
}

Key Points

• $elemMatch finds the first array element matching all specified conditions.
• The positional operator $ refers to the matched array element's position.
• $push adds new elements to the targeted nested array.

Conclusion

Use $elemMatch with the positional operator $ to update specific array elements based on multiple conditions. This approach ensures precise targeting of nested array elements for updates.