MongoDB query to remove subdocument from document?

To remove subdocument from a document, use $pull along with update(). Let us first create a collection with documents −

> db.demo538.insertOne( ... { ...    id:101, ...    "details": ...    { ...       anotherDetails: ...       [ ...          { ...             "Name":"Chris", ...             Age:21 ...          }, ...          { ...             "Name":"David", ...             Age:23 ...          }, ...          { ...             "Name":"Bob", ...             Age:20 ...          } ...       ] ...    } ... } ... ); {    "acknowledged" : true,    "insertedId" : ObjectId("5e8c8f0aef4dcbee04fbbc08") }

Display all documents from a collection with the help of find() method −

> db.demo538.find();

This will produce the following output −

{ "_id" : ObjectId("5e8c8f0aef4dcbee04fbbc08"), "id" : 101, "details" : { "anotherDetails" : [    { "Name" : "Chris", "Age" : 21 }, { "Name" : "David", "Age" : 23 }, { "Name" : "Bob", "Age" : 20 } ] } }

Following is the query to remove subdocument from a document −

> db.demo538.update({ id:101}, ... {$pull : { "details.anotherDetails" : {"Age":23} } } ) WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })

Display all documents from a collection with the help of find() method −

> db.demo538.find();

This will produce the following output −

{ "_id" : ObjectId("5e8c8f0aef4dcbee04fbbc08"), "id" : 101, "details" : { "anotherDetails" : [ { "Name" : "Chris", "Age" : 21 }, { "Name" : "Bob", "Age" : 20 } ] } }