To update partial number of documents, set multi to true. Let us create a collection with documents −> db.demo312.insertOne({"FirstName":"Robert"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5e50ce16f8647eb59e56204a") } > db.demo312.insertOne({"FirstName":"Bob"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5e50ce19f8647eb59e56204b") } > db.demo312.insertOne({"FirstName":"Robert"}); {    "acknowledged" : true,    "insertedId" ... Read More

For faster queries, create an index. To get the count, use count(). Let us create a collection with documents −> db.demo311.ensureIndex({"Name":1}); {    "createdCollectionAutomatically" : true,    "numIndexesBefore" : 1,    "numIndexesAfter" : 2,    "ok" : 1 } > db.demo311.insertOne({"Name":"Chris"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5e50cd01f8647eb59e562044") ... Read More

To push document into an array, use $push along with update(). Let us create a collection with documents −>db.demo310.insertOne({"Name":"Chris", "details":[{"Id":101, "Subject":"MySQL"}, {"Id":102, "Subject":"MongoDB"}]}); {    "acknowledged" : true,    "insertedId" : ObjectId("5e50cabdf8647eb59e562043") }Display all documents from a collection with the help of find() method −> db.demo310.find();This will produce the following ... Read More

To remove, use remove() in MongoDB. Let us create a collection with documents −> db.demo309.insertOne({ "details":[ { "Name":"Chris" }, { "Name":"David" }, { "Name":"Adam" } ] } ); {    "acknowledged" : true,    "insertedId" : ObjectId("5e4eb71af8647eb59e562040") } > db.demo309.insertOne({ "details":[ { "Name":"David" }, { "Name":"Mike" }, { "Name":"Bob" } ... Read More

To retried a subset of fields, use dot notation in find(). Let us create a collection with documents −> db.demo307.insertOne({ ...   "CleintId":101, ...   "ClientDetails":{"ClientFirstName":"Chris", "Age":34}, ...   "ClientCountryName":"US" ...} ...); {    "acknowledged" : true,    "insertedId" : ObjectId("5e4eab88f8647eb59e56203c") } > db.demo307.insertOne({ ...   "CleintId":102, ...   "ClientDetails":{"ClientFirstName":"David", ... Read More

To fetch documents, use find() in MongoDB. With that, to format the resultant documents, use pretty().Let us create a collection with documents −> db.demo306.insertOne({"Name":"Robert", "Age":21}); {    "acknowledged" : true,    "insertedId" : ObjectId("5e4ea7c6f8647eb59e562038") } > db.demo306.insertOne({"Name":"David", "Age":23}); {    "acknowledged" : true,    "insertedId" : ObjectId("5e4ea7cdf8647eb59e562039") } > db.demo306.insertOne({"Name":"Mike", ... Read More

To get the child of a collection in MongoDB, use find(). Let us create a collection with documents −> db.demo305.insertOne( ...   { ...      _id: 101, ...      FirstName : 'Chris', ...      details : { ...         "0":"102", ...       ... Read More

Use $or operator to fetch values and to format the result, use “pretty()”. Let us create a collection with documents −> db.demo304.insertOne({"StudentName":"Chris", "StudentAge":23}); {    "acknowledged" : true,    "insertedId" : ObjectId("5e4ea3ccf8647eb59e562034") } > db.demo304.insertOne({"StudentName":"David", "StudentAge":22}); {    "acknowledged" : true,    "insertedId" : ObjectId("5e4ea3d7f8647eb59e562035") } > db.demo304.insertOne({"StudentName":"Mike", "StudentAge":24}); { ... Read More

For distinct values, use distinct(). Let us create a collection with documents −> db.demo303.insertOne({FirstName:"Chris", LastName:"Brown"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5e4ea0f6f8647eb59e56202f") } > db.demo303.insertOne({FirstName:"John", LastName:"Doe"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5e4ea104f8647eb59e562030") } > db.demo303.insertOne({FirstName:"Chris", LastName:"Smith"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5e4ea10df8647eb59e562031") ... Read More

For this, use dot notation for field selection in MongoDB find(). Let us create a collection with documents −> db.demo302.insertOne({"Id":101, "details":[{"Name":"Chris", Age:21, "Subject":"MySQL"}]}); {    "acknowledged" : true,    "insertedId" : ObjectId("5e4d746f5d93261e4bc9ea52") } > db.demo302.insertOne({"Id":102, "details":[{"Name":"Bob", Age:23, "Subject":"MongoDB"}]}); {    "acknowledged" : true,    "insertedId" : ObjectId("5e4d74815d93261e4bc9ea53") } > db.demo302.insertOne({"Id":103, ... Read More