无法将自定义对象添加到mongoDB文档数组

Question

I'm trying to add a new object to my mongodb document inside an array.

I have a NodeJS project using MongoDB which has a collection called "Teste" where i'm saving some random data.

Amongst that data is an array called "ArrayTeste". Currently it is only saving multiple strings because I named my inputs the same thing, so it automatically does it for me.

But I don't want to save each element as an individual string, i need to get these informations, group them in an object and then add it to the array.

Here is my code snippet in NodeJS:

ServicosModel.prototype.Teste = function (req, res) {
console.log("Metodo Teste");
var query =
    {
        $push:
        {
            ArrayTeste:
            {
                Dado1: req.body.Dado1,
                Dado2: req.body.Dado2
            }
        }
    }

console.log(query)

this._connection.open(function (errConn, mongoClient) {
    console.log("Entrou open")
    if (errConn) {
        res.end("Deu erro" + errConn);
    }
    mongoClient.collection("teste", function (errColl, collection) {
        if (errColl) {
            res.end("Deu erro" + errColl);
        }
        console.log("Entrou collection")
        collection.update(query, function (errUpdate, result) {
            console.log("Entrou update")
            if (errUpdate) {
                res.end("Deu erro" + errUpdate);
            } else {
                res.end("Deu certo " + result);
            }
        });
    });
});

}

And here is the mongoDB document structure:

{
"_id" : ObjectId("595bf19febbf3c14e481bc28"),
"id" : "2",
"Titulo" : "TItulo do negocio",
"ArrayTeste" : [ 
    "dado1", 
    "dado2"
]

}

The "id" parameter is one created by me to easy the $elemMatch used in previous tests, so I don't have to search for the _id of the document.

When I run the code and insert stuff into the inputs, I am presented with this error:

(node:8712) UnhandledPromiseRejectionWarning: Unhandled promise rejection (rejection id: 1): MongoError: document must be a valid JavaScript object

and I have absolutely no idea of what is happening. the application simply freezes. I have searched through the posts and tried some stuff with $set and $addToSet, but the same error persists.

Any help is appreciated, thanks in advance!

Answer 1

To update a document you need two mandatory parameters:

• criteria - to select documents to update
• update - to modify selected documents

Here is the driver documentation: https://mongodb.github.io/node-mongodb-native/markdown-docs/insert.html#update .

The error says that collection.update expects an object (the second parameter) and it is receiving a function (your callback function).

To get your code working:

var select = {id: '2'};  // Here we are choosing the document

collection.update(select, query, function (errUpdate, result) {
    if (errUpdate) {
        res.end("Deu erro" + errUpdate);
    } else {
        res.end("Deu certo " + result);
    }
});