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How to delete particular data in a document in MongoDB?
You can use $unset. Let us first create a collection with documents −
> db.demo20.insertOne(
... {
...
... "ListOfEmployee" : [
... {
... "EmployeeName1" : "John"
... },
... {
... "EmployeeName2" : "Carol"
... }
... ],
... "EmployeeName2" : []
... }
... );
{
"acknowledged" : true,
"insertedId" : ObjectId("5e138c3555d0fc6657d21f12")
}Following is the query to display all documents from a collection with the help of find() method −
> db.demo20.find();
This will produce the following output −
{ "_id" : ObjectId("5e138c3555d0fc6657d21f12"), "ListOfEmployee" : [ { "EmployeeName1" : "John" }, { "EmployeeName2" : "Carol" } ], "EmployeeName2" : [ ] }Following is the query to delete particular data in a document −
> db.demo20.update({ "EmployeeName2": { "$exists": 1 }},{ "$unset": { "EmployeeName2": "" } });
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })Following is the query to display all documents from a collection with the help of find() method −
> db.demo20.find();
This will produce the following output −
{ "_id" : ObjectId("5e138c3555d0fc6657d21f12"), "ListOfEmployee" : [ { "EmployeeName1" : "John" }, { "EmployeeName2" : "Carol" } ] }
Updated on: 01-Apr-2020
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