Is it possible to cast in a MongoDB Query?

Yes, it is possible to cast in a MongoDB query −

db.yourCollectionName.find("this.yourFieldName >yourValue);

To understand the concept, let us create a collection with the document. The query to create a collection with a document is as follows −

> db.castingDemo.insertOne({"Amount":"200"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5c947e874cf1f7a64fa4df42") } > db.castingDemo.insertOne({"Amount":"100"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5c947e8e4cf1f7a64fa4df43") } > db.castingDemo.insertOne({"Amount":"110"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5c947e944cf1f7a64fa4df44") } > db.castingDemo.insertOne({"Amount":"95"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5c947e9d4cf1f7a64fa4df45") } > db.castingDemo.insertOne({"Amount":"85"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5c947ea44cf1f7a64fa4df46") } > db.castingDemo.insertOne({"Amount":"75"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5c947ebd4cf1f7a64fa4df47") }

Display all documents from a collection with the help of find() method. The query is as follows −

> db.castingDemo.find().pretty();

The following is the output −

{ "_id" : ObjectId("5c947e874cf1f7a64fa4df42"), "Amount" : "200" } { "_id" : ObjectId("5c947e8e4cf1f7a64fa4df43"), "Amount" : "100" } { "_id" : ObjectId("5c947e944cf1f7a64fa4df44"), "Amount" : "110" } { "_id" : ObjectId("5c947e9d4cf1f7a64fa4df45"), "Amount" : "95" } { "_id" : ObjectId("5c947ea44cf1f7a64fa4df46"), "Amount" : "85" } { "_id" : ObjectId("5c947ebd4cf1f7a64fa4df47"), "Amount" : "75" }

Here is the query that automatically converts from string to number −

> db.castingDemo.find("this.Amount > 85");

The following is the output −

{ "_id" : ObjectId("5c947e874cf1f7a64fa4df42"), "Amount" : "200" } { "_id" : ObjectId("5c947e8e4cf1f7a64fa4df43"), "Amount" : "100" } { "_id" : ObjectId("5c947e944cf1f7a64fa4df44"), "Amount" : "110" } { "_id" : ObjectId("5c947e9d4cf1f7a64fa4df45"), "Amount" : "95" }