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Found 1359 Articles for MongoDB
130 Views
To find a certain element, use $project in MongoDB. Let us create a collection with documents −> db.demo744.insertOne( ... { ... studentInformation: ... [ ... { ... studentName:"Robert", ... grade:"A" ... }, ... { ... studentName:"Bob", ... grade:"C" ... }, ... { ... ... Read More
60 Views
For this, use $$ROOT in MongoDB. Let us create a collection with documents −> db.demo743.insertOne({id:1, "ShippingDate":"2020-01-21", value:50}); { "acknowledged" : true, "insertedId" : ObjectId("5ead893a57bb72a10bcf0680") } > db.demo743.insertOne({id:2, "ShippingDate":"2020-05-10", value:30}); { "acknowledged" : true, "insertedId" : ObjectId("5ead893c57bb72a10bcf0681") } > db.demo743.insertOne({id:3, "ShippingDate":"2020-05-10", value:60}); { "acknowledged" : true, "insertedId" : ObjectId("5ead894657bb72a10bcf0682") } > db.demo743.insertOne({id:1, "ShippingDate":"2020-05-11", value:75}); { "acknowledged" : true, "insertedId" : ObjectId("5ead895657bb72a10bcf0683") }Display all documents from a collection with the help of find() method −> db.demo743.find();This will produce the following output −{ "_id" : ObjectId("5ead893a57bb72a10bcf0680"), "id" : 1, "ShippingDate" : "2020-01-21", "value" : 50 ... Read More
1K+ Views
To fetch a specific element, iterate with forEach(). Let us create a collection with documents −> db.demo742.insertOne({ "userDetails": [ { "userName":"Robert", "CountryName":"UK" }, { "userName":"David", "CountryName":"AUS" } ]} ); { "acknowledged" : true, "insertedId" : ObjectId("5ead790b57bb72a10bcf0677") }Display all documents from a collection with the help of find() method −> db.demo742.find().pretty();This will produce the following output −{ "_id" : ObjectId("5ead790b57bb72a10bcf0677"), "userDetails" : [ { "userName" : "Robert", "CountryName" : "UK" }, { "userName" : "David", ... Read More
83 Views
To update for _id, use $set in MongoDB. Let us create a collection with documents −db.demo741.insertOne({SubjectName:"MySQL"}); { "acknowledged" : true, "insertedId" : ObjectId("5ead718657bb72a10bcf0672") } > db.demo741.insertOne({SubjectName:"C"}); { "acknowledged" : true, "insertedId" : ObjectId("5ead718957bb72a10bcf0673") } > db.demo741.insertOne({SubjectName:"Java"}); { "acknowledged" : true, "insertedId" : ObjectId("5ead718e57bb72a10bcf0674") }Display all documents from a collection with the help of find() method −> db.demo741.find();This will produce the following output −{ "_id" : ObjectId("5ead718657bb72a10bcf0672"), "SubjectName" : "MySQL" } { "_id" : ObjectId("5ead718957bb72a10bcf0673"), "SubjectName" : "C" } { "_id" : ObjectId("5ead718e57bb72a10bcf0674"), "SubjectName" : "Java" }Following is the query to updating MongoDB for _id ... Read More
417 Views
Let us create a collection with documents −> db.demo740.insertOne({ ... "details": ... [ ... { ... Name:"Chris", ... Age:21, ... CountryName:"US" ... }, ... { ... Name:"Bob", ... Age:20, ... CountryName:"UK", ... isMarried:true ... } ... ] ... }); { "acknowledged" : true, "insertedId" : ObjectId("5ead700c57bb72a10bcf066d") }Display all documents from a collection with the help ... Read More
810 Views
To push value, use save() along with for loop. Let us create a collection with documents −> for(var v=1; v db.demo739.find();This will produce the following output −{ "_id" : ObjectId("5ead6e7857bb72a10bcf0666"), "Name" : "Chris", "SubjectName" : "MongoDB" } { "_id" : ObjectId("5ead6e7857bb72a10bcf0667"), "Name" : "Chris", "SubjectName" : "MongoDB" } { "_id" : ObjectId("5ead6e7857bb72a10bcf0668"), "Name" : "Chris", "SubjectName" : "MongoDB" } { "_id" : ObjectId("5ead6e7857bb72a10bcf0669"), "Name" : "Chris", "SubjectName" : "MongoDB" } { "_id" : ObjectId("5ead6e7857bb72a10bcf066a"), "Name" : "Chris", "SubjectName" : "MongoDB" } { "_id" : ObjectId("5ead6e7857bb72a10bcf066b"), "Name" : "Chris", "SubjectName" : "MongoDB" }
122 Views
Let us create a collection with documents −> db.demo738.insertOne({Subjects:["C", "C++"]}); { "acknowledged" : true, "insertedId" : ObjectId("5ead696557bb72a10bcf0661") } > db.demo738.insertOne({Subjects:["MySQL", "PL/SQL"]}); { "acknowledged" : true, "insertedId" : ObjectId("5ead696657bb72a10bcf0662") }Display all documents from a collection with the help of find() method −> db.demo738.find();This will produce the following output −{ "_id" : ObjectId("5ead696557bb72a10bcf0661"), "Subjects" : [ "C", "C++" ] } { "_id" : ObjectId("5ead696657bb72a10bcf0662"), "Subjects" : [ "MySQL", "PL/SQL" ] }Following is the query to push −>db.demo738.update({_id:ObjectId("5ead696657bb72a10bcf0662")}, {$push:{"Subjects":"MongoDB"}}); WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })Display all documents from a collection with the help of ... Read More
2K+ Views
To order by timestamp, use sort() in MongoDB. Let us create a collection with documents −> db.demo737.insertOne({"timestamp" : new ISODate("2020-04-01" )}); { "acknowledged" : true, "insertedId" : ObjectId("5ead682157bb72a10bcf065c") } > db.demo737.insertOne({"timestamp" : new ISODate("2020-10-31" )}); { "acknowledged" : true, "insertedId" : ObjectId("5ead682757bb72a10bcf065d") } > db.demo737.insertOne({"timestamp" : new ISODate("2020-05-02" )}); { "acknowledged" : true, "insertedId" : ObjectId("5ead682a57bb72a10bcf065e") }Display all documents from a collection with the help of find() method −> db.demo737.find();This will produce the following output −{ "_id" : ObjectId("5ead682157bb72a10bcf065c"), "timestamp" : ISODate("2020-04-01T00:00:00Z") } { "_id" : ObjectId("5ead682757bb72a10bcf065d"), "timestamp" : ISODate("2020-10-31T00:00:00Z") } { "_id" : ... Read More
660 Views
MongoDB insertOne() inserts a document into a collection, whereas updateOne() update a single document in a collection based on a query filter.Let us create a collection with documents −> db.demo735.insertOne({id:1, Name:"Chris"}); { "acknowledged" : true, "insertedId" : ObjectId("5ead51b657bb72a10bcf0652") } > db.demo735.insertOne({id:1, Name:"David"}); { "acknowledged" : true, "insertedId" : ObjectId("5ead51bb57bb72a10bcf0653") } > db.demo735.insertOne({id:1, Name:"Bob"}); { "acknowledged" : true, "insertedId" : ObjectId("5ead51be57bb72a10bcf0654") } > db.demo735.insertOne({id:1, Name:"Carol"}); { "acknowledged" : true, "insertedId" : ObjectId("5ead51c757bb72a10bcf0655") }Display all documents from a collection with the help of find() method −> db.demo735.find();This will produce the following output −{ "_id" ... Read More