Use insertMany() to insert multiple documents into a collection. With that, to update performance you can use ensureIndex().Let us create a collection with documents and insert multiple documents −> db.demo325.insertMany( [ ...    { _id: 101, Name: "Chris", Age: 23 }, ...    { _id: 102, Name: "David", Age: 24 ... Read More

Let us create a collection with documents −> db.demo324.insertOne({"ListOfValues":[10, 20, 30]}); {    "acknowledged" : true,    "insertedId" : ObjectId("5e516349f8647eb59e562073") }Display all documents from a collection with the help of find() method −> db.demo324.find().pretty();This will produce the following output −{    "_id" : ObjectId("5e516349f8647eb59e562073"),    "ListOfValues" : [     ... Read More

At first, let us create a collection with documents and also use ensureIndex() to create an index −> db.demo323.insertOne({"details":{"Name":"Chris", "Age":34}}); {    "acknowledged" : true,    "insertedId" : ObjectId("5e51157af8647eb59e56206e") } > db.demo323.insertOne({"details":{"Name":"David", "Age":31}}); {    "acknowledged" : true,    "insertedId" : ObjectId("5e511581f8647eb59e56206f") } > db.demo323.insertOne({"details":{"Name":"Bob", "Age":28}}); {    "acknowledged" : ... Read More

To check for existing documents/embedded documents, use $exists in MongoDB. Let us create a collection with documents −> db.demo322.insertOne( ...  {'id':1001, ...    'details':[{'Score':10000, Name:"Bob"}, ...       {'Score':98000, Name:"Sam"} ...    ] ... } ... ); {    "acknowledged" : true,    "insertedId" : ObjectId("5e5113e2f8647eb59e56206c") } > db.demo322.insertOne( ... Read More

Let us first create a collection with documents wherein we are storing array values −>db.demo321.insertOne({"UserDetails":[{"UserId":101, "UserName":"Chris"}, {"UserId":102, "UserName":"Mike"}]}); {    "acknowledged" : true,    "insertedId" : ObjectId("5e511248f8647eb59e56206a") } >db.demo321.insertOne({"UserDetails":[{"UserId":103, "UserName":"Bob"}, {"UserId":104, "UserName":"Sam"}]}); {    "acknowledged" : true,    "insertedId" : ObjectId("5e511259f8647eb59e56206b") }Display all documents from a collection with the help ... Read More

The fastest way of updating is update(). Let us create a collection with documents and see how update() works −> db.demo320.insertOne({"Name":"Chris"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5e50ee51f8647eb59e562066") } > db.demo320.insertOne({"Name":"Robert"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5e50ee55f8647eb59e562067") } > db.demo320.insertOne({"Name":"Mike"}); {    "acknowledged" : true, ... Read More

In MongoDB, you cannot use capped for sub-collection. However, use capped on the overall document. To display a specific number of values from an array, prefer $slice.Let us create a collection with documents −> db.demo319.insertOne({"Scores":[100, 345, 980, 890]}); {    "acknowledged" : true,    "insertedId" : ObjectId("5e50ecf6f8647eb59e562064") } > db.demo319.insertOne({"Scores":[903, ... Read More

To pull a specific value, use UPDATE with $pull. Let us create a collection with documents −> db.demo318.insertOne({Subject:["MySQL", "MongoDB", "Java"]}); {    "acknowledged" : true,    "insertedId" : ObjectId("5e50ea6df8647eb59e562062") } > db.demo318.insertOne({Subject:["Spring", "Hibernate"]}); {    "acknowledged" : true,    "insertedId" : ObjectId("5e50ea78f8647eb59e562063") }Display all documents from a collection with the ... Read More

To get values greater than a specific value, use $gt along with find(). Let us create a collection with documents −> db.demo317.insertOne( ...    {'id':101, ...       'details':[{'Score':78, Name:"Chris"}, ...          {'Score':88, Name:"David"} ...       ] ...    } ... ); {   ... Read More

For this, use ensureIndex() and set unique:true. Let us create a collection with documents. Here, when we try to inert duplicate item, then a duplicate key error occurs −> db.demo316.ensureIndex({"SubjectName":1}, {unique:true}); {    "createdCollectionAutomatically" : true,    "numIndexesBefore" : 1,    "numIndexesAfter" : 2,    "ok" : 1 } > ... Read More