How to append existing array in existing collection in mongodb using java with new values

Question

I have a mongo collection like:

{
    "_id": ObjectId("55cad746aed75601b4822cc9"),
    "entityId": "12",
    "entityType": "a",
    "nameIdentity": [{
        "fName": "abc",
        "lName": "def",
        "dob": "00",
        "address": "xyz"
    },

    ]
}

I am using mongodb java 3.0 driver and trying to match and update. For eg: I am trying to match on entityId if it found then add the new nameIdentity.

Second time when I pass

{
    "fName": "123",
    "lName": "456",
    "dob": "00",
    "address": "789"
}

For my entityId: 12 if it matches then my new collection should like this:

{
    "_id": ObjectId("55cad746aed75601b4822cc9"),
    "entityId": "12",
    "entityType": "a",
    "nameIdentity": [{
    "fName": "abc",
    "lName": "def",
    "dob": "00",
    "address": "xyz"
    }, {
    "fName": "123",
    "lName": "456",
    "dob": "00",
    "address": "789"
    }]
}

I want to add it in the same matched object or collection. But its replacing the previous array and adding new like this:

{
    "_id": ObjectId("55cad746aed75601b4822cc9"),
    "entityId": "12",
    "entityType": "a",
    "nameIdentity": [

    {
        "fName": "123",
        "lName": "456",
        "dob": "00",
        "address": "789"
    }
    ]
}

When entity id is matched I want everything to be added not updated. The code I tried is :

mongoDatabase.getCollection("entity").findOneAndUpdate(
    updateDocument, new Document("$set",entityDocument));

I tried with $push and $set. Its creating a new nameIdentity Array. But I want to add in same matched nameIdentity array. Any suggestions where am I going wrong ?

Answer 1

You should use $push like following:

db.collection.update({
    "entityId": "12"
}, {
    $push: {
    "nameIdentity": {
        "fName": "123",
        "lName": "456",
        "dob": "00",
        "address": "789"
    }
    }
})

Its equivalent query using mongo java driver is something like (tested) :

db.getCollection("entity").updateOne(new Document("entityId", "12"),
new Document("$push", new Document("nameIdentity", new Document("fName", "123").append("lName", "456")
    .append("dob", "00").append("address", "789"))));

If you want to update many documents then use updateMany instead of updateOne by passing required params.

Answer 2

You basically want to $push and add to the named array entry here. But for .findOneAndUpdate() you also need to set the ReturnDocument type in order to receive the result.

Otherwise the "original" document is returned, just as it is for all drivers.

    Document entityDocument = new Document();
    entityDocument.append("fname","123");
    entityDocument.append("lname","456");
    entityDocument.append("dob","00");
    entityDocument.append("address","789")

    Document doc = mongoDatabase.getCollection("entity").findOneAndUpdate(
            new Document("entityId", 12),
            new Document("$push", new Document("nameIdentity", entityDocument)),
            new FindOneAndUpdateOptions().returnDocument(ReturnDocument.AFTER)
    );

    System.out.println(doc.toJson());