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Found 1659 Articles for Big Data Analytics
![AmitDiwan](https://www.tutorialspoint.com/assets/profiles/123055/profile/60_187394-1565938756.jpg)
107 Views
To check for existence of a record, use findOne() in MongoDB. Let us first create a collection with documents −> db.existsAlternateDemo.insertOne({"StudentName":"Chris"}); { "acknowledged" : true, "insertedId" : ObjectId("5e06d23f9e4dae213890ac5c") } > db.existsAlternateDemo.insertOne({"StudentName":"Chris", "StudentAge":21}); { "acknowledged" : true, "insertedId" : ObjectId("5e06d2559e4dae213890ac5d") } >db.existsAlternateDemo.insertOne({"StudentName":"Chris", "StudentAge":22, "StudentCountryName":"US"}); { "acknowledged" : true, "insertedId" : ObjectId("5e06d2689e4dae213890ac5e") }Following is the query to display all documents from a collection with the help of find() method −> db.existsAlternateDemo.find();This will produce the following output −{ "_id" : ObjectId("5e06d23f9e4dae213890ac5c"), "StudentName" : "Chris" } { "_id" : ObjectId("5e06d2559e4dae213890ac5d"), "StudentName" : "Chris", "StudentAge" : 21 } { ... Read More
![AmitDiwan](https://www.tutorialspoint.com/assets/profiles/123055/profile/60_187394-1565938756.jpg)
2K+ Views
To sum specific fields, use aggregate along with $sum. Let us first create a collection with documents −> db.getSumOfFieldsDemo.insertOne({"Customer_Id":101, "Price":50, "Status":"Active"}); { "acknowledged" : true, "insertedId" : ObjectId("5e06cec29e4dae213890ac55") } > db.getSumOfFieldsDemo.insertOne({"Customer_Id":102, "Price":200, "Status":"Inactive"}); { "acknowledged" : true, "insertedId" : ObjectId("5e06ced19e4dae213890ac56") } > db.getSumOfFieldsDemo.insertOne({"Customer_Id":101, "Price":3000, "Status":"Active"}); { "acknowledged" : true, "insertedId" : ObjectId("5e06cedd9e4dae213890ac57") } > db.getSumOfFieldsDemo.insertOne({"Customer_Id":103, "Price":400, "Status":"Active"}); { "acknowledged" : true, "insertedId" : ObjectId("5e06cee79e4dae213890ac58") }Following is the query to display all documents from a collection with the help of find() method −> db.getSumOfFieldsDemo.find().pretty();This will produce the following output −{ "_id" : ... Read More
![AmitDiwan](https://www.tutorialspoint.com/assets/profiles/123055/profile/60_187394-1565938756.jpg)
7K+ Views
To insert records in MongoDB and avoid duplicates, use “unique:true”. Let us first create a collection with documents.Here, we are trying to add duplicate records −> db.insertWithoutDuplicateDemo.createIndex({"StudentFirstName":1}, { unique: true } ); { "createdCollectionAutomatically" : true, "numIndexesBefore" : 1, "numIndexesAfter" : 2, "ok" : 1 } > db.insertWithoutDuplicateDemo.insert({"StudentFirstName":"Chris"}, { upsert: true }); WriteResult({ "nInserted" : 1 }) > db.insertWithoutDuplicateDemo.insert({"StudentFirstName":"David"}, { upsert: true }); WriteResult({ "nInserted" : 1 }) > db.insertWithoutDuplicateDemo.insert({"StudentFirstName":"Chris"}, { upsert: true }); WriteResult({ "nInserted" : 0, "writeError" : { "code" : 11000, "errmsg" : "E11000 duplicate ... Read More
![AmitDiwan](https://www.tutorialspoint.com/assets/profiles/123055/profile/60_187394-1565938756.jpg)
288 Views
To apply a condition, use $setIsSubset. Let us first create a collection with documents −> db.subsetDemo.insertOne({"StudentName":"Chris", "StudentFavouriteSubject":["Java", "Python"]}); { "acknowledged" : true, "insertedId" : ObjectId("5e063e49150ee0e76c06a052") } > db.subsetDemo.insertOne({"StudentName":"Chris", "StudentFavouriteSubject":["Java", "Python", "MySQL"]}); { "acknowledged" : true, "insertedId" : ObjectId("5e063e4f150ee0e76c06a053") }Following is the query to display all documents from a collection with the help of find() method −> db.subsetDemo.find().pretty();This will produce the following output −{ "_id" : ObjectId("5e063e49150ee0e76c06a052"), "StudentName" : "Chris", "StudentFavouriteSubject" : [ "Java", "Python" ] } { "_id" : ObjectId("5e063e4f150ee0e76c06a053"), "StudentName" : "Chris", ... Read More
![AmitDiwan](https://www.tutorialspoint.com/assets/profiles/123055/profile/60_187394-1565938756.jpg)
951 Views
At first, get the current month and subtract by 1 to fetch previous month records. Let us first create a collection with documents −> db.findOneMonthAgoData.insertOne({"CustomerName":"Chris", "PurchaseDate":new ISODate("2019-12-26")}); { "acknowledged" : true, "insertedId" : ObjectId("5e04e16c150ee0e76c06a04f") } > db.findOneMonthAgoData.insertOne({"CustomerName":"David", "PurchaseDate":new ISODate("2019-11-26")}); { "acknowledged" : true, "insertedId" : ObjectId("5e04e178150ee0e76c06a050") } > db.findOneMonthAgoData.insertOne({"CustomerName":"Bob", "PurchaseDate":new ISODate("2020-11-26")}); { "acknowledged" : true, "insertedId" : ObjectId("5e04e186150ee0e76c06a051") }Following is the query to display all documents from a collection with the help of find() method −> db.findOneMonthAgoData.find();This will produce the following output −{ "_id" : ObjectId("5e04e16c150ee0e76c06a04f"), "CustomerName" : "Chris", "PurchaseDate" : ISODate("2019-12-26T00:00:00Z") } { ... Read More
![AmitDiwan](https://www.tutorialspoint.com/assets/profiles/123055/profile/60_187394-1565938756.jpg)
1K+ Views
To aggregate nested documents in MongoDB, you can use $group. Let us first create a collection with documents −> db.aggregateDemo.insertOne( ... { ... "ProductInformation": [ ... { ... "Product1": [ ... { ... Amount: 50 ... }, ... { ... Amount: 90 ... ... Read More
![AmitDiwan](https://www.tutorialspoint.com/assets/profiles/123055/profile/60_187394-1565938756.jpg)
392 Views
To update, just save new ID and remove the old one using remove(). Let us first create a collection with documents −> db.updatingDemo.insertOne({"StudentName":"Robert"}); { "acknowledged" : true, "insertedId" : ObjectId("5e04dae5150ee0e76c06a04b") } > db.updatingDemo.insertOne({"StudentName":"Bob"}); { "acknowledged" : true, "insertedId" : ObjectId("5e04dae7150ee0e76c06a04c") }Following is the query to display all documents from a collection with the help of find() method −> db.updatingDemo.find();This will produce the following output −{ "_id" : ObjectId("5e04dae5150ee0e76c06a04b"), "StudentName" : "Robert" } { "_id" : ObjectId("5e04dae7150ee0e76c06a04c"), "StudentName" : "Bob" }Here is the query to update _id in MongoDB −> myDocument = db.updatingDemo.findOne({"StudentName":"Bob"}); { "_id" : ObjectId("5e04dae7150ee0e76c06a04c"), ... Read More
![AmitDiwan](https://www.tutorialspoint.com/assets/profiles/123055/profile/60_187394-1565938756.jpg)
8K+ Views
To add a column, you need to update the collection. The syntax is as follows −db.getCollection(yourCollectionName).update({}, {$set: {"yourColumnName": "yourValue"}}, false, true);To understand the above syntax, let us create a collection with documents −> db.addColumnDemo.insertOne({"StudentId":101, "StudentName":"Chris"}); { "acknowledged" : true, "insertedId" : ObjectId("5e04d66af5e889d7a519950f") } > db.addColumnDemo.insertOne({"StudentId":102, "StudentName":"Robert"}); { "acknowledged" : true, "insertedId" : ObjectId("5e04d673f5e889d7a5199510") } > db.addColumnDemo.insertOne({"StudentId":103, "StudentName":"David"}); { "acknowledged" : true, "insertedId" : ObjectId("5e04d67bf5e889d7a5199511") }Following is the query to display all documents from a collection with the help of find() method −> db.addColumnDemo.find().pretty();This will produce the following output −{ "_id" : ObjectId("5e04d66af5e889d7a519950f"), ... Read More
![AmitDiwan](https://www.tutorialspoint.com/assets/profiles/123055/profile/60_187394-1565938756.jpg)
360 Views
To check for a specific value, use $in. Let us first create a collection with documents −> db.testInArray.insertOne({"ListOfNumbers":[10, 56, 78, 90, 32]}); { "acknowledged" : true, "insertedId" : ObjectId("5e04d42df5e889d7a519950d") } > db.testInArray.insertOne({"ListOfNumbers":[56, 78, 91, 100]}); { "acknowledged" : true, "insertedId" : ObjectId("5e04d588f5e889d7a519950e") }Following is the query to display all documents from a collection with the help of find() method −> db.testInArray.find().pretty();This will produce the following output −{ "_id" : ObjectId("5e04d42df5e889d7a519950d"), "ListOfNumbers" : [ 10, 56, 78, 90, 32 ... Read More
![AmitDiwan](https://www.tutorialspoint.com/assets/profiles/123055/profile/60_187394-1565938756.jpg)
64 Views
For this, simply use find(). For a different format, use pretty(). Let us first create a collection with documents −> db.getSpecificData.insertOne( ... { ... "StudentName": "John", ... "Information": { ... "FatherName": "Chris", ... "Place": { ... "CountryName": "US", ... "ZipCode":"111344" ... }, ... "id": "1" ... } ... } ... ); { "acknowledged" : true, "insertedId" : ObjectId("5e039abdf5e889d7a5199509") } > db.getSpecificData.insertOne( ... { ... "StudentName": "Carol", ... "Information": ... Read More