How to remove _id from MongoDB results?

Question

I am inserting json file into Mongodb(with Scala/Play framework) and the same getting/downloading it into my view page for some other requirement, but this time it is coming with one "_id" parameter in the json file.

But I need only my actual json file only that is not having any any "_id" parameter. I have read the Mongodb tutorial, that by default storing it with one _id for any collection document.

Please let me know that how can I get or is there any chance to get my actual json file without any _id in MongoDB.

this is the json result which is storing in database(I don't need that "_id" parameter)

{
        "testjson": [{
        "key01": "value1",
        "key02": "value02",
        "key03": "value03"
    }],
  "_id": 1
 }

Himanshu Bhandari · Answer 1 · 2016-04-13T07:58:52.267

2

You can use this query in the shell:

db.testtable.find({},{"_id" : false})

Here we are telling mongoDB not to return _id from the collection. You can also use 0 instead of false, like this:

db.testtable.find({},{"_id" : 0})

for scala you need to convert it in as per the driver syntax.

edited Apr 13 '16 at 07:58

answered Apr 13 '16 at 06:38

Himanshu Bhandari

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thanks for your reply, yes it is giving without any _id from the collection if I run it on my shell console. But I am not sure how can I apply it in scala. – Dhana Apr 13 '16 at 06:42
Just find it in documentation. Isn't it there? – Himanshu Bhandari Apr 13 '16 at 06:44
yeah, I am checking in Play/Scala documentation, but I couldn't find. – Dhana Apr 13 '16 at 06:46

score 2 · Accepted Answer · answered Apr 13 '16 at 07:26

2

If you have a look at ReactiveMongo dev guide and to its API, you can see it support projection in a similar way as the MongoDB shell.

Then you can understand that you can do

collection.find(selector = BSONDocument(), projection = BSONDocument("_id" -> 0))

Or, as you are using JSON serialization:

collection.find(selector = Json.obj(), projection = Json.obj("_id" -> 0))

answered Apr 13 '16 at 07:26

cchantep

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thanks you for your reply, I have added as per your comment, but this time also I can see _id is appended in my json. Edited the above query in description – Dhana Apr 13 '16 at 07:53
I have added the same thing at one more place in my other file, now it is working fine now. Thanks for your help !! – Dhana Apr 13 '16 at 08:58

How to remove _id from MongoDB results?

2 Answers2