MongoDB query to get minimum and maximum value from documents including some duplicate records

For this, use aggregate() and $group. To get minimum and maximum value, use $min and $max.

Let us create a collection with documents −

> db.demo167.insertOne({"Score":60});
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5e3693a79e4f06af551997d1")
}
> db.demo167.insertOne({"Score":80});
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5e3693ab9e4f06af551997d2")
}
> db.demo167.insertOne({"Score":60});
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5e3693ad9e4f06af551997d3")
}
> db.demo167.insertOne({"Score":90});
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5e3693b09e4f06af551997d4")
}
> db.demo167.insertOne({"Score":89});
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5e3693b69e4f06af551997d5")
}

Display all documents from a collection with the help of find() method −

> db.demo167.find();

This will produce the following output −

{ "_id" : ObjectId("5e3693a79e4f06af551997d1"), "Score" : 60 }
{ "_id" : ObjectId("5e3693ab9e4f06af551997d2"), "Score" : 80 }
{ "_id" : ObjectId("5e3693ad9e4f06af551997d3"), "Score" : 60 }
{ "_id" : ObjectId("5e3693b09e4f06af551997d4"), "Score" : 90 }
{ "_id" : ObjectId("5e3693b69e4f06af551997d5"), "Score" : 89 }

Following is the query to get minimum and maximum value −

> var d = [
...    {
...       "$group": {
...          "_id": "id",
...          "MinimumValue": { "$min": "$Score" },
...          "MaximumValue": { "$max": "$Score" }
...       }
...    }
... ]
> db.demo167.aggregate(d);

This will produce the following output −

{ "_id" : "id", "MinimumValue" : 60, "MaximumValue" : 90 }