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How to remove duplicate entries by two keys in MongoDB?
To remove duplicate entries by two keys, use aggregate() in MongoDB. Let us create a collection with documents −
> db.demo108.insertOne({"Value1":23,"Value2":24});
{
"acknowledged" : true,
"insertedId" : ObjectId("5e2ee3e49fd5fd66da214477")
}
> db.demo108.insertOne({"Value1":23,"Value2":25});
{
"acknowledged" : true,
"insertedId" : ObjectId("5e2ee3f29fd5fd66da214478")
}
> db.demo108.insertOne({"Value1":23,"Value2":24});
{
"acknowledged" : true,
"insertedId" : ObjectId("5e2ee3f59fd5fd66da214479")
}
Display all documents from a collection with the help of find() method −
> db.demo108.find();
This will produce the following output −
{ "_id" : ObjectId("5e2ee3e49fd5fd66da214477"), "Value1" : 23, "Value2" : 24 }
{ "_id" : ObjectId("5e2ee3f29fd5fd66da214478"), "Value1" : 23, "Value2" : 25 }
{ "_id" : ObjectId("5e2ee3f59fd5fd66da214479"), "Value1" : 23, "Value2" : 24 }
Following is the query to remove duplicate entries by two keys in MongoDB −
> db.demo108.aggregate([{ "$sort": { "_id": 1 } },
... {
... "$group": {
... "_id": { "Value1": "$Value1", "Value2": "$Value2" },
... "doc": { "$first": "$$ROOT" }
... }
... },
... { "$replaceRoot": { "newRoot": "$doc" } },
... { "$out": "demo108" }]);
Display all documents from a collection with the help of find() method −
> db.demo108.find();
This will produce the following output −
{ "_id" : ObjectId("5e2ee3f29fd5fd66da214478"), "Value1" : 23, "Value2" : 25 }
{ "_id" : ObjectId("5e2ee3e49fd5fd66da214477"), "Value1" : 23, "Value2" : 24 }
Updated on: 2020-03-30T11:47:54+05:30
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