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MongoDB query to pull a specific value from a document
To pull a specific value, use UPDATE with $pull. Let us create a collection with documents −
> db.demo318.insertOne({Subject:["MySQL","MongoDB","Java"]});
{
"acknowledged" : true,
"insertedId" : ObjectId("5e50ea6df8647eb59e562062")
}
> db.demo318.insertOne({Subject:["Spring","Hibernate"]});
{
"acknowledged" : true,
"insertedId" : ObjectId("5e50ea78f8647eb59e562063")
}Display all documents from a collection with the help of find() method −
> db.demo318.find();
This will produce the following output −
{ "_id" : ObjectId("5e50ea6df8647eb59e562062"), "Subject" : [ "MySQL", "MongoDB", "Java" ] }
{ "_id" : ObjectId("5e50ea78f8647eb59e562063"), "Subject" : [ "Spring", "Hibernate" ] }Following is the query to $pull a specific value “Hibernate” −
> db.demo318.update({Subject:"Hibernate"},{$pull:{"Subject":"Hibernate"}});
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })Display all documents from a collection with the help of find() method −
> db.demo318.find();
This will produce the following output −
{ "_id" : ObjectId("5e50ea6df8647eb59e562062"), "Subject" : [ "MySQL", "MongoDB", "Java" ] }
{ "_id" : ObjectId("5e50ea78f8647eb59e562063"), "Subject" : [ "Spring" ] }
Updated on: 02-Apr-2020
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