Extract a MongoDB document with a specific string

To extract a MongoDB document with a specific string, use the $match operator in an aggregation pipeline to filter documents containing the target string value.

Syntax

db.collection.aggregate([
    { $match: { "field": "specific_string" } }
]);

Create Sample Data

db.demo424.insertMany([
    {
        "Information": [
            {
                id: 10,
                Name: "Chris"
            },
            {
                id: 11,
                Name: "David"
            }
        ]
    },
    {
        "Information": [
            {
                id: 101,
                Name: "Mike"
            },
            {
                id: 102,
                Name: "John"
            }
        ]
    }
]);

{
    "acknowledged": true,
    "insertedIds": [
        ObjectId("..."),
        ObjectId("...")
    ]
}

Display All Documents

db.demo424.find();

{ "_id": ObjectId("5e74eb9dbbc41e36cc3cae6a"), "Information": [ { "id": 10, "Name": "Chris" }, { "id": 11, "Name": "David" } ] }
{ "_id": ObjectId("5e74eb9ebbc41e36cc3cae6b"), "Information": [ { "id": 101, "Name": "Mike" }, { "id": 102, "Name": "John" } ] }

Extract Document with Specific String

Find documents where any element in the Information array has Name "Chris" ?

db.demo424.aggregate([
    { $match: { "Information.Name": "Chris" } }
]);

{ "_id": ObjectId("5e74eb9dbbc41e36cc3cae6a"), "Information": [ { "id": 10, "Name": "Chris" }, { "id": 11, "Name": "David" } ] }

Alternative Using find()

You can also use the simpler find() method for the same result ?

db.demo424.find({ "Information.Name": "Chris" });

Conclusion

Use $match in aggregation pipelines or find() with dot notation to extract documents containing specific string values in nested arrays. Both methods effectively filter documents based on string matching criteria.