Removing an array element from MongoDB collection using update() and $pull

Let us first create a collection with documents -

> db.removingAnArrayElementDemo.insertOne({"UserMessage":["Hi","Hello","Bye"]}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cef97bdef71edecf6a1f6a4") }

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

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

Output

{    "_id" : ObjectId("5cef97bdef71edecf6a1f6a4"),    "UserMessage" : [       "Hi",       "Hello",       "Bye"    ] }

Following is the query to remove an array element from MongoDB -

> db.removingAnArrayElementDemo.update(    {_id:ObjectId("5cef97bdef71edecf6a1f6a4")},    { "$pull": { "UserMessage": "Hello" } } ); WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })

Let us check the document once again:

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

Output

{    .    "_id" : ObjectId("5cef97bdef71edecf6a1f6a4"),    "UserMessage" : [       "Hi",       "Bye"    ] }