- Trending Categories
Data Structure
Networking
RDBMS
Operating System
Java
MS Excel
iOS
HTML
CSS
Android
Python
C Programming
C++
C#
MongoDB
MySQL
Javascript
PHP
Physics
Chemistry
Biology
Mathematics
English
Economics
Psychology
Social Studies
Fashion Studies
Legal Studies
- Selected Reading
- UPSC IAS Exams Notes
- Developer's Best Practices
- Questions and Answers
- Effective Resume Writing
- HR Interview Questions
- Computer Glossary
- Who is Who
Found 1349 Articles for MongoDB
![AmitDiwan](https://www.tutorialspoint.com/assets/profiles/123055/profile/60_187394-1565938756.jpg)
130 Views
Use $all for array match. The $all operator selects the documents where the value of a field is an array that contains all the specified elements. Let us create a collection with documents −> db.demo668.createIndex({"ListOfSubject":1}); { "createdCollectionAutomatically" : true, "numIndexesBefore" : 1, "numIndexesAfter" : 2, "ok" : 1 } > db.demo668.insert({"ListOfSubject":["MySQL", "Java", "C"]}); WriteResult({ "nInserted" : 1 }) > db.demo668.insert({"ListOfSubject":["MongoDB", "Python", "C++"]}); WriteResult({ "nInserted" : 1 }) > db.demo668.insert({"ListOfSubject":["C#", "Spring", "Hibernate", "MongoDB"]}); WriteResult({ "nInserted" : 1 })Display all documents from a collection with the help of find() method −> db.demo668.find();This will produce the following output −{ ... Read More
![AmitDiwan](https://www.tutorialspoint.com/assets/profiles/123055/profile/60_187394-1565938756.jpg)
290 Views
The ObjectId does not accept the seed string. You need to use _id − StringValue. Let us create a collection with documents −> db.demo667.insertOne({_id:"Chris"}); { "acknowledged" : true, "insertedId" : "Chris" } > db.demo667.insertOne({_id:"David"}); { "acknowledged" : true, "insertedId" : "David" } > db.demo667.insertOne({_id:"Chris"}); 2020-04-23T22:01:23.268+0530 E QUERY [js] WriteError: E11000 duplicate key error collection: test.demo667 index: _id_ dup key: { : "Chris" } : WriteError({ "index" : 0, "code" : 11000, "errmsg" : "E11000 duplicate key error collection: test.demo667 index: _id_ dup key: { : \"Chris\" }", "op" : { "_id" : ... Read More
![AmitDiwan](https://www.tutorialspoint.com/assets/profiles/123055/profile/60_187394-1565938756.jpg)
2K+ Views
To display only the employee names with specific salaries, set the salaries in MongoDB $in and fetch the names. Let us create a collection with documents> db.demo666.insertOne({"EmployeeName":"John", "EmployeeSalary":25000}); { "acknowledged" : true, "insertedId" : ObjectId("5ea1c04824113ea5458c7d0d") } > db.demo666.insertOne({"EmployeeName":"Chris", "EmployeeSalary":35000}); { "acknowledged" : true, "insertedId" : ObjectId("5ea1c05524113ea5458c7d0e") } > db.demo666.insertOne({"EmployeeName":"David", "EmployeeSalary":65000}); { "acknowledged" : true, "insertedId" : ObjectId("5ea1c06024113ea5458c7d0f") } > db.demo666.insertOne({"EmployeeName":"Carol", "EmployeeSalary":40000}); { "acknowledged" : true, "insertedId" : ObjectId("5ea1c06f24113ea5458c7d10") }Display all documents from a collection with the help of find() method −> db.demo666.find();This will produce the following output −{ "_id" : ObjectId("5ea1c04824113ea5458c7d0d"), "EmployeeName" ... Read More
![AmitDiwan](https://www.tutorialspoint.com/assets/profiles/123055/profile/60_187394-1565938756.jpg)
82 Views
To search for ranges, use sort() with limit(). Let us create a collection with documents −> db.demo665.insertOne({"Value":10}); { "acknowledged" : true, "insertedId" : ObjectId("5ea1bf1424113ea5458c7d08") } > db.demo665.insertOne({"Value":15}); { "acknowledged" : true, "insertedId" : ObjectId("5ea1bf1b24113ea5458c7d09") } > db.demo665.insertOne({"Value":55}); { "acknowledged" : true, "insertedId" : ObjectId("5ea1bf1e24113ea5458c7d0a") } > db.demo665.insertOne({"Value":25}); { "acknowledged" : true, "insertedId" : ObjectId("5ea1bf2324113ea5458c7d0b") } > db.demo665.insertOne({"Value":20}); { "acknowledged" : true, "insertedId" : ObjectId("5ea1bf2b24113ea5458c7d0c") }Display all documents from a collection with the help of find() method −> db.demo665.find();This will produce the following output −{ "_id" : ObjectId("5ea1bf1424113ea5458c7d08"), "Value" : 10 ... Read More
![AmitDiwan](https://www.tutorialspoint.com/assets/profiles/123055/profile/60_187394-1565938756.jpg)
356 Views
It is saved in the special system.js collection. For this, use db.system.js.save(). Following is the syntax −db.system.js.save({ _id: "anyFunctionName", value: function (returnValue) { return ‘yourMessage ' + returnValue; } })Let us implement the above syntax. Following is the query −> db.system.js.save({ ... _id: "returnValue", ... value: function (data) { ... return 'The value==== ' + data; ... } ... }) WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })Following is the query to call the above function to print the actual data −> db.eval("returnValue(20)") WARNING: db.eval is deprecatedThis will produce the following output −The value==== 20
![AmitDiwan](https://www.tutorialspoint.com/assets/profiles/123055/profile/60_187394-1565938756.jpg)
691 Views
To count number of documents, use count() in MongoDB. Let us create a collection with documents −> db.demo664.insertOne({_id:1, ClientName:"Chris"}); { "acknowledged" : true, "insertedId" : 1 } > db.demo664.insertOne({_id:2, ClientName:"Bob"}); { "acknowledged" : true, "insertedId" : 2 } > db.demo664.insertOne({_id:3, ClientName:"Sam"}); { "acknowledged" : true, "insertedId" : 3 } > db.demo664.insertOne({_id:4, ClientName:"David"}); { "acknowledged" : true, "insertedId" : 4 }Display all documents from a collection with the help of find() method −> db.demo664.find();This will produce the following output −{ "_id" : 1, "ClientName" : "Chris" } { "_id" : 2, "ClientName" : "Bob" } { "_id" : 3, "ClientName" : ... Read More
![AmitDiwan](https://www.tutorialspoint.com/assets/profiles/123055/profile/60_187394-1565938756.jpg)
352 Views
For bulk insert in MongoDB, use initializeUnorderedBulkOp(). Let us create a collection with documents −> var bulkInsertDoc = db.demo663.initializeUnorderedBulkOp(); > bulkInsertDoc.insert( { Name: "John", CountryName:"US"} ); > bulkInsertDoc.insert( { Name: "Chris", CountryName:"UK"} ); > bulkInsertDoc.insert( { Name: "David", CountryName:"AUS"} ); > bulkInsertDoc.execute(); BulkWriteResult({ "writeErrors" : [ ], "writeConcernErrors" : [ ], "nInserted" : 3, "nUpserted" : 0, "nMatched" : 0, "nModified" : 0, "nRemoved" : 0, "upserted" : [ ] })Display all documents from a collection with the help of find() method −> db.demo663.find();This will produce the following output −{ "_id" : ... Read More
![AmitDiwan](https://www.tutorialspoint.com/assets/profiles/123055/profile/60_187394-1565938756.jpg)
217 Views
To filter out sub documents, use MongoDB aggregate and in that, use $unwind. Let us create a collection with documents −> db.demo662.insertOne( ... { ... "details":[ ... { ... Name:"Chris", ... Marks:35 ... }, ... { ... Name:"Bob", ... Marks:45 ... }, ... { ... Name:"David", ... Marks:30 ... } ... ] ... } ... ); { "acknowledged" : true, "insertedId" : ObjectId("5ea1b2be24113ea5458c7d04") }Display all documents from a collection with the help of ... Read More
![AmitDiwan](https://www.tutorialspoint.com/assets/profiles/123055/profile/60_187394-1565938756.jpg)
365 Views
For faster search, create index. For this, use createIndex(). Let us create a collection with documents −> db.demo661.createIndex({ListOfName:1}); { "createdCollectionAutomatically" : true, "numIndexesBefore" : 1, "numIndexesAfter" : 2, "ok" : 1 } > db.demo661.insertOne({_id:1, ListOfName:["John", "Robert", "David"]}); { "acknowledged" : true, "insertedId" : 1 } > db.demo661.insertOne({_id:2, ListOfName:["Mike", "Sam"]}); { "acknowledged" : true, "insertedId" : 2 } > db.demo661.insertOne({_id:3, ListOfName:["John", "David", "Bob"]}); { "acknowledged" : true, "insertedId" : 3 }Display all documents from a collection with the help of find() method −> db.demo661.find();This will produce the following output −{ "_id" : 1, "ListOfName" : [ "John", ... Read More
![AmitDiwan](https://www.tutorialspoint.com/assets/profiles/123055/profile/60_187394-1565938756.jpg)
335 Views
You can use $group. Let us create a collection with documents −> db.demo659.insertOne({Name:"Chris", CountryName:"US", "Marks":50}); { "acknowledged" : true, "insertedId" : ObjectId("5ea1a50724113ea5458c7cf9") } > db.demo659.insertOne({Name:"David", CountryName:"US", "Marks":60}); { "acknowledged" : true, "insertedId" : ObjectId("5ea1a50724113ea5458c7cfa") } > db.demo659.insertOne({Name:"Mike", CountryName:"US", "Marks":55}); { "acknowledged" : true, "insertedId" : ObjectId("5ea1a50724113ea5458c7cfb") } > db.demo659.insertOne({Name:"Chris", CountryName:"UK", "Marks":75}); { "acknowledged" : true, "insertedId" : ObjectId("5ea1a50724113ea5458c7cfc") } > db.demo659.insertOne({Name:"David", CountryName:"UK", "Marks":54}); { "acknowledged" : true, "insertedId" : ObjectId("5ea1a50724113ea5458c7cfd") } > db.demo659.insertOne({Name:"Mike", CountryName:"UK", "Marks":72}); { "acknowledged" : true, "insertedId" : ObjectId("5ea1a50824113ea5458c7cfe") }Display all documents from a collection ... Read More