How to remove an element from a doubly-nested array in a MongoDB document?

To remove an element from a doubly-nested array in MongoDB document, you can use $pull operator.

To understand the concept, let us create a collection with the document. The query to create a collection with a document is as follows −

> db.removeElementFromDoublyNestedArrayDemo.insertOne(    ... {       ... "_id" : "1",       ... "UserName" : "Larry",       ... "UserDetails" : [          ... {             ... "UserCountryName" : "US",             ... "UserLocation" : [                ... {                   ... "UserCityName" : "New York"                ... },                ... {                   ... "UserZipCode" : "10001"                ... }             ... ]          ... }       ... ]    ... } ... ); { "acknowledged" : true, "insertedId" : "1" } > db.removeElementFromDoublyNestedArrayDemo.insertOne(    ... {       ... "_id" : "2",       ... "UserName" : "Mike",       ... "UserDetails" : [          ... {             ... "UserCountryName" : "UK",             ... "UserLocation" : [                ... {                   ... "UserCityName" : "Bangor"                ... },                ... {                   ... "UserZipCode" : "20010"                ... }             ... ]          ... }       ... ]    ... } ... ); { "acknowledged" : true, "insertedId" : "2" }

Display all documents from a collection with the help of find() method. The query is as follows −

> db.removeElementFromDoublyNestedArrayDemo.find().pretty();

The following is the output −

{    "_id" : "1",    "UserName" : "Larry",    "UserDetails" : [       {          "UserCountryName" : "US",          "UserLocation" : [             {                "UserCityName" : "New York"             },             {                "UserZipCode" : "10001"             }          ]       }    ] } {    "_id" : "2",    "UserName" : "Mike",    "UserDetails" : [       {          "UserCountryName" : "UK",          "UserLocation" : [             {                "UserCityName" : "Bangor"             },             {                "UserZipCode" : "20010"             }          ]       }    ] }

Here is the query to remove an element from a doubly-nested array in MongoDB document −

> db.removeElementFromDoublyNestedArrayDemo.update(    ... { _id : "2" },    ... {$pull : {"UserDetails.0.UserLocation" : {"UserZipCode":"20010"}}} ... ); WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })

Lets us check the documents from a collection with the help of find(). The query is as follows −

> db.removeElementFromDoublyNestedArrayDemo.find().pretty();

The following is the output −

{    "_id" : "1",    "UserName" : "Larry",    "UserDetails" : [       {          "UserCountryName" : "US",          "UserLocation" : [             {                "UserCityName" : "New York"             },             {                "UserZipCode" : "10001"             }          ]       }    ] } {    "_id" : "2",    "UserName" : "Mike",    "UserDetails" : [       {          "UserCountryName" : "UK",          "UserLocation" : [             {                "UserCityName" : "Bangor"             }          ]       }    ] }

Now field "UserZipCode": "20010" has been removed from a doubly-nested array.