mongoDB - Update query adding an array document to an existing document

Question

The userlist collection contains documents of the following format.

{
        "_id" : ObjectId("5381d32ce72cc794166eede2"),
        "name" : "Haseeb",
        "password" : "dgkhan",
        "email" : "[email protected]",
        "address" : "237 D, Faisal Town , Lahore",
        "phone" : "5162806"
}

I intend to add another member in the existing document such that the resultant document looks like this.

{
            "_id" : ObjectId("5381d32ce72cc794166eede2"),
            "name" : "Haseeb",
            "password" : "dgkhan",
            "email" : "[email protected]",
            "address" : "237 D, Faisal Town , Lahore",
            "phone" : "5162806",
            "purchases" : [{
                "itemID": xyz,
                "quantity": 142
            },
            {
                "itemID": kjh,
                "quantity": 987
            }
            }]

}

For this I have written the following mongoskin query, but it is not performing any updates.

db.collection('userlist').update(
                {_id:req.session._id},
                 {
                    '$push': { purchases: {
                        itemID: item.ID,
                        quantity: item.quantity
                    }
                }
            }, function(err) {
                if (err) throw err;
                    console.log('Updated!');
            });
        }

Value of req.session._id = 5381d32ce72cc794166eede2 i.e a valid _id field of a docuemnt in my collection whereas item.ID and item.quantity are also valid strings. Any help would be really appreciated.

JohnnyHK · Accepted Answer · 2014-05-26 02:20:22Z

2

I'm more familiar with Mongoose, but looking at the docs you could probably either use:

collection.updateById(req.session._id, ...)

or

collection.update({_id: toObjectID(req.session_id)}, ...)

edited May 26, 2014 at 2:20

JohnnyHK

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answered May 25, 2014 at 15:42

Tyler Graf

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2 Comments

jaywalker Over a year ago

I forgot to convert my id into a proper object Id hex string. toObjectID(req.session_id) fixed it

Tyler Graf Over a year ago

Yep! that's what I was referring to. Sorry I didn't make it more clear.

ABrowBoyGenius · Accepted Answer · 2014-05-25 17:58:20Z

0

I think you should be using $set instead of $push.

A good resource for this specific question is: http://docs.mongodb.org/manual/reference/method/db.collection.update/#db.collection.update

answered May 25, 2014 at 17:58

ABrowBoyGenius

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1 Comment

jaywalker Over a year ago

No, $set overrites the existing value which is not what I intend to do here. I want to add a purchase document to the existing set of purchases.

ABrowBoyGenius · Accepted Answer · 2014-05-25 19:47:23Z

0

Something like this. You need to include the $each syntax.

db.collection('userlist').update(
                {_id:req.session._id},
                 {
                    $push { purchases: { $each: {
                        itemID: item.ID,
                        quantity: item.quantity
                        }
                    }
                }
            }, function(err) {
                if (err) throw err;
                    console.log('Updated!');
            });
    }

answered May 25, 2014 at 19:47

ABrowBoyGenius

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