Nested arrays in MongoDB?

Question

When I log the object right before saving it, it looks like this:

{
    "type": "events",
    "labels": [
        "abc",
        "123"
    ],
    "keywords": [
        [
            "a",
            "b",
            "c",
            "d",
            "e"
        ],
        [
            "1",
            "2",
            "3",
            "4",
            "5"
        ]
    ],
    "_id": "4d9ddac669cb3bf5e855a366"
}

but then if i go into the mongo shell it saves like this...

{
    "_id": ObjectId("4d9ddac669cb3bf5e855a366"),
    "keywords": [

    ],
    "labels": [
        "abc",
        "123"
    ],
    "type": "events"
}

any ideas?

Brendan W. McAdams · Accepted Answer · 2011-04-07 23:53:21Z

1

Saving that directly in the MongoDB shell keeps the nesting structure:

{
    "_id" : "4d9ddac669cb3bf5e855a366",
    "type" : "events",
    "labels" : [
        "abc",
        "123"
    ],
    "keywords" : [
        [
            "a",
            "b",
            "c",
            "d",
            "e"
        ],
        [
            "1",
            "2",
            "3",
            "4",
            "5"
        ]
    ]
}

And as far as I know all the official drivers handle the nested arrays correctly. It sounds like the BSON writer in Node may be skipping the outer array.

Can you run a few similar tests saving the same thing in the shell and with Node and see if they differ?

answered Apr 7, 2011 at 23:53

Brendan W. McAdams

9,4873 gold badges43 silver badges31 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

fancy Over a year ago

Inserting via the shell it works fine. I'm using Mongoose on top of Mongo within Node.

Collectives™ on Stack Overflow

Nested arrays in MongoDB?

1 Answer 1

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related