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Found 6702 Articles for Database
147 Views
For this, use the aggregate framework. Let us first create a collection with documents −> db.aggregateArrayDemo.insertOne( { "_id":100, "UserDetails": [ { "UserName": "John", "UserLoginYear":2010 }, { "UserName": "Carol", "UserLoginYear":2019 } ] } ); { "acknowledged" : true, "insertedId" : 100 }Following is the query to display all documents from a collection with the help of find() method −> db.aggregateArrayDemo.find().pretty();This will produce the following output −{ "_id" : 100, "UserDetails" : [ { "UserName" : "John", "UserLoginYear" : 2010 }, { "UserName" : "Carol", "UserLoginYear" : 2019 } ] }Following is the query to aggregate array documents −> db.aggregateArrayDemo.aggregate([ { $match: { _id: 100 } }, { $project: { Minimum: { $min: "$UserDetails.UserLoginYear" }, Maximum: { $max: "$UserDetails.UserLoginYear" } } } ]);This will produce the following output −{ "_id" : 100, "Minimum" : 2010, "Maximum" : 2019 }
102 Views
To get the matching document, use $elemMatch. Let us first create a collection with documents −> db.getMatchingDocumentDemo.insertOne( { _id :1, "UserDetails":[ { "UserName":"John", "UserAge":23 } ] } ); { "acknowledged" : true, "insertedId" : 1 } > db.getMatchingDocumentDemo.insertOne( { _id :2, "UserDetails":[ { "UserName":"Larry", "UserAge":24 } ] } ); { "acknowledged" : true, "insertedId" : 2 }Following is the query to display all documents from a collection with the ... Read More
446 Views
You can use update(). Let us first create a collection with documents −> db.addExtraFieldDemo.insertOne( { "_id": 1, "UserName": "Larry" , "UserOtherDetails":[ { "UserCountryName": "US", "UserAge":23 }, { "UserCountryName": "UK", "UserAge":24 } ] } ); { "acknowledged" : true, "insertedId" : 1 }Following is the query to ... Read More
481 Views
Let us first create a collection with documents −> db.deleteMultipleDocumentsDemo.insertOne({"StudentFirstName":"Larry"}); { "acknowledged" : true, "insertedId" : ObjectId("5ce00b07bf3115999ed51214") } > db.deleteMultipleDocumentsDemo.insertOne({"StudentFirstName":"Chris"}); { "acknowledged" : true, "insertedId" : ObjectId("5ce00b0bbf3115999ed51215") } > db.deleteMultipleDocumentsDemo.insertOne({"StudentFirstName":"David"}); { "acknowledged" : true, "insertedId" : ObjectId("5ce00b0fbf3115999ed51216") } > db.deleteMultipleDocumentsDemo.insertOne({"StudentFirstName":"Bob"}); { "acknowledged" : true, "insertedId" : ObjectId("5ce00b12bf3115999ed51217") } > db.deleteMultipleDocumentsDemo.insertOne({"StudentFirstName":"Carol"}); { "acknowledged" : true, "insertedId" : ObjectId("5ce00b18bf3115999ed51218") }Following is the query to display all documents from a collection with the help of find() method −> db.deleteMultipleDocumentsDemo.find();This will produce the following output −{ "_id" : ObjectId("5ce00b07bf3115999ed51214"), "StudentFirstName" : "Larry" } { ... Read More
252 Views
Following is the syntax to use $regex in MongoDB −db.yourCollectionName.find({yourFieldName: { $regex: yourValue}});Let us first create a collection with documents −> db.regularExpressionDemo.insertOne({"UserName":"John"}); { "acknowledged" : true, "insertedId" : ObjectId("5cdffc25bf3115999ed51210") } > db.regularExpressionDemo.insertOne({"UserName":"JOHN"}); { "acknowledged" : true, "insertedId" : ObjectId("5cdffc2ebf3115999ed51211") } > db.regularExpressionDemo.insertOne({"UserName":"john"}); { "acknowledged" : true, "insertedId" : ObjectId("5cdffc35bf3115999ed51212") } > db.regularExpressionDemo.insertOne({"UserName":"JoHn"}); { "acknowledged" : true, "insertedId" : ObjectId("5cdffc3ebf3115999ed51213") }Following is the query to display all documents from a collection with the help of find() method −> db.regularExpressionDemo.find();This will produce the following output −{ "_id" : ObjectId("5cdffc25bf3115999ed51210"), "UserName" : "John" } { ... Read More
252 Views
As an alternative, use the $eq operator. Let us first create a collection with documents −> db.equalDemo.insertOne({_id:1, "StudentFriendNames":["John", "Carol", "Sam"]}); { "acknowledged" : true, "insertedId" : 1 } > db.equalDemo.insertOne({_id:2, "StudentFriendNames":null}); { "acknowledged" : true, "insertedId" : 2 } > db.equalDemo.insertOne({_id:3, "StudentFriendNames":["Carol"]}); { "acknowledged" : true, "insertedId" : 3 } > db.equalDemo.insertOne({_id:4, "StudentFriendNames":["Sam"]}); { "acknowledged" : true, "insertedId" : 4 }Following is the query to display all documents from a collection with the help of find() method −> db.equalDemo.find();This will produce the following output −{ "_id" : 1, "StudentFriendNames" : [ "John", "Carol", "Sam" ] } { "_id" : 2, ... Read More
299 Views
Use $or operator along with $expr operator for this. Let us first create a collection with documents, wherein one of fields is isMarried having true of false value −> db.orTwoFieldsDemo.insertOne({"isLiveInUS":true, "isMarried":false}); { "acknowledged" : true, "insertedId" : ObjectId("5cdfd86abf3115999ed5120d") } > db.orTwoFieldsDemo.insertOne({"isLiveInUS":true, "isMarried":true}); { "acknowledged" : true, "insertedId" : ObjectId("5cdfd876bf3115999ed5120e") } > db.orTwoFieldsDemo.insertOne({"isLiveInUS":false, "isMarried":false}); { "acknowledged" : true, "insertedId" : ObjectId("5cdfd87dbf3115999ed5120f") }Following is the query to display all documents from a collection with the help of find() method −> db.orTwoFieldsDemo.find();This will produce the following output −{ "_id" : ObjectId("5cdfd86abf3115999ed5120d"), "isLiveInUS" : true, "isMarried" : false ... Read More
257 Views
To get the minimum value, use sort() along with limit(1). Let us first create a collection with documents −> db.findMinimumValueDemo.insertOne({"Value":1004}); { "acknowledged" : true, "insertedId" : ObjectId("5cdfd61abf3115999ed51208") } > db.findMinimumValueDemo.insertOne({"Value":983}); { "acknowledged" : true, "insertedId" : ObjectId("5cdfd61ebf3115999ed51209") } > db.findMinimumValueDemo.insertOne({"Value":990}); { "acknowledged" : true, "insertedId" : ObjectId("5cdfd622bf3115999ed5120a") } > db.findMinimumValueDemo.insertOne({"Value":1093}); { "acknowledged" : true, "insertedId" : ObjectId("5cdfd626bf3115999ed5120b") } > db.findMinimumValueDemo.insertOne({"Value":10090}); { "acknowledged" : true, "insertedId" : ObjectId("5cdfd62fbf3115999ed5120c") }Following is the query to display all documents from a collection with the help of find() method −> db.findMinimumValueDemo.find();This will produce the following ... Read More
348 Views
Let us first create a collection with documents −> db.queryForPartialObjectDemo.insertOne({_id:new ObjectId(), "StudentDetails": [{"StudentId":1, "StudentName":"Chris"}]}); { "acknowledged" : true, "insertedId" : ObjectId("5cdfcf55bf3115999ed51206") } > db.queryForPartialObjectDemo.insertOne({_id:new ObjectId(), "StudentDetails": [{"StudentId":2, "StudentName":"David"}]}); { "acknowledged" : true, "insertedId" : ObjectId("5cdfcf55bf3115999ed51207") }Following is the query to display all documents from a collection with the help of find() method −> db.queryForPartialObjectDemo.find().pretty();This will produce the following output −{ "_id" : ObjectId("5cdfcf55bf3115999ed51206"), "StudentDetails" : [ { "StudentId" : 1, "StudentName" : "Chris" } ] } { "_id" ... Read More
139 Views
Let us first create a collection with documents −> dbmongoDBCollectionSizeDemoinsertOne({"Name":"John", "Age":23}); { "acknowledged" : true, "insertedId" : ObjectId("5cf23e3db64a577be5a2bc16") } > dbmongoDBCollectionSizeDemoinsertOne({"Name":"Chris", "Age":24}); { "acknowledged" : true, "insertedId" : ObjectId("5cf23e45b64a577be5a2bc17") } > dbmongoDBCollectionSizeDemoinsertOne({"Name":"Robert", "Age":26}); { "acknowledged" : true, "insertedId" : ObjectId("5cf23e4db64a577be5a2bc18") }Following is the query to display all documents from a collection with the help of find() method −> dbmongoDBCollectionSizeDemofind();This will produce the following document −{ "_id" : ObjectId("5cf23e3db64a577be5a2bc16"), "Name" : "John", "Age" : 23 } { "_id" : ObjectId("5cf23e45b64a577be5a2bc17"), "Name" : "Chris", "Age" : 24 } { "_id" : ObjectId("5cf23e4db64a577be5a2bc18"), "Name" : "Robert", "Age" ... Read More