CODEWITHSUNDEEP
node.jsmongodb
quietplace
quietplace

Reputation: 539

How to increment nested value in MongoDB

I'm trying to increment a value in a mongoDB document.

Here is the document structure

enter image description here

I'm looking to increment knowCnt on the object with the matching username and respective cardId (1001 in this case) .

Here's my code so far. It returns success but the value isn't incremented in the DB.

var knowIncr = function(cnt) {
        db.collection("testusers").updateOne( //collection.update depreciated!!!
          { $and: [
          { username: "user1" },
          { cardId: 1001 },  
          ]},
          { $inc: { knowCnt: 1 } }, //increment by 1 
          { new: true },
          (err, data) => {
            if (err) {
              console.log(err);
            }
            console.log("knowIncr success", data);
          }
        );
      };
      knowIncr();

I also tried .updateOne({ username: "user1", cardId: 1001}, ... to no avail.

Thanks

Upvotes: 0

Views: 78

Answers (1)

tosi
tosi

Reputation: 621

You have to specify the array name before accessing one of their objects, here's an example:

db.testUsers.updateOne({
    "username": "user1",
    "progress.cardId": 1001
}, {
    $inc: {
        "progress.$.knowCnt": 1
    }
});

Here's more info about updating arrays and regarding using the $ sign: https://docs.mongodb.com/manual/reference/operator/update/positional/

Upvotes: 1

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