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Split a document by its subdocuments in MongoDB
To split a document by its subdocuments, use $unwind in MongoDB. Let us create a collection with documents −
> db.demo276.insertOne({"Name":"Chris","Subjects":["MySQL","MongoDB"]});
{
"acknowledged" : true,
"insertedId" : ObjectId("5e48f953dd099650a5401a51")
}Display all documents from a collection with the help of find() method −
> db.demo276.find().pretty();
This will produce the following output −
{
"_id" : ObjectId("5e48f953dd099650a5401a51"),
"Name" : "Chris",
"Subjects" : [
"MySQL",
"MongoDB"
]
}Following is the query to split a document by its subdocuments −
> db.demo276.aggregate( [ { $unwind : "$Subjects" } ] )This will produce the following output −
{ "_id" : ObjectId("5e48f953dd099650a5401a51"), "Name" : "Chris", "Subjects" : "MySQL" }
{ "_id" : ObjectId("5e48f953dd099650a5401a51"), "Name" : "Chris", "Subjects" : "MongoDB" }
Updated on: 31-Mar-2020
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