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mongodbfindembeddocument

In MongoDB, how can I find a document that is embedded?

I created an embedded document named "KPOP" in MongoDB, and I wanted to find the field with the value of "BTS: Fake Love"

Here is the embedded document:

> use TestMongoDB
  switched to db TestMongoDB
> db.KPOP.find().pretty()
{
    "_id" : ObjectId("5fd83447066c904c1365771a"),
    "KPOP" : {
            "SHINee" : "Dream Girl",
            "Girl's Generation" : "I Got a Boy",
            "BTS" : "Fake Love"
    }
}

Is something wrong with my code? After I press enter, nothing shows up.

> db.KPOP.find( {"KPOP": {"BTS": "Fake Love"}} )
Solution

  • Is something wrong with my code? After I press enter, nothing shows up.

    db.KPOP.find( {"KPOP": {"BTS": "Fake Love"}} )

    That is the expected behavior.

    If you want to query an embedded document's individual field(s) you need to use the following syntax - using the dot (.) notation. For example, both these queries return the document:

    db.test.find({"KPOP.SHINee": "Dream Girl"})
db.test.find({"KPOP.SHINee": "Dream Girl", "KPOP.BTS": "Fake Love" })

    In the above queries, you can specify one, two or all the fields and in any order.

    You use the following syntax when specifying the filter for the whole embedded document:

    db.test.find({ KPOP: { SHINee: "Dream Girl", "Girl's Generation": "I Got a Boy", BTS: "Fake Love" } })

    In this case, note that the order of the fields of the embedded document must be same as that of the original document; i.e., SHINee, "Girl's Generation" and BTS (within the KPOP). And, you need to specify all the fields of the embedded document.