MongoDB Update Document – Examples

MongoDB Update Document

You can update one or more fields in documents of a MongoDB collection based on a specific criteria, using update() method.

MongoDB Update Document – In this tutorial, we shall learn how to update MongoDB Documents based on a selection criteria using update() method.

Syntax of update() method

The syntax of update() method is

db.collection_name.update(criteria, update, options)

where

collection_name	Mame of the collection in which you update document
criteria	[mandatory] Criteria to select documents for update
update	[mandatory] Updates to the fields for the selected documents

Options – All options below are optional.

Option	[Type][DefaultValue] DefaultAction	Description
upsert	[boolean][false] Does not insert a new document when no match found	If set to true, Inserts as a new document when no match is found for the criteria.
multi	[boolean][false] Updates only one document.	If set to true, updates all the documents that obey the criteria.
collation	[document][default] Uses binary comparison for comparing strings.	You may specify language-specific rules. Refer Collation. You can specify only only language in a Collation.
WriteConcern	[document][default] Refer Write Concern.	Write concern describes the level of acknowledgement requested from MongoDB.

To update a MongoDB Document, follow the step by step guide below :

1. Prepare a Criteria to select those documents for update.
   criteria = {field1:value1, field2:value2,..}
2. Prepare Update Document.
   update = {field1:value1, field2:value2,..}
3. [Optional] Query the Documents based on the Criteria formed to cross verify if you want to update all those selected Documents.
   db.collection.find(criteria)
4. Prepare the options based on your use case.
5. Run db.collection.update() method with criteria, update and options.
   db.collection.update(criteria, update, options)

Example 1 – Update single MongoDB Document

Following is an example to update only one Document.

We shall use following people  Collection in this Document Update Example and run the commands in Mongo Shell.

> db.people.find({})
{ "_id" : ObjectId("59eeba4e5f82df4555f2bfb2"), "name" : "Midhuna", "age" : 23, "place" : "Amaravati" }
{ "_id" : ObjectId("59eeba4e5f82df4555f2bfb3"), "name" : "Akhil", "age" : 24, "place" : "New York" }
{ "_id" : ObjectId("59eeba4e5f82df4555f2bfb4"), "name" : "Honey", "age" : 27, "profession" : "Docter" }
{ "_id" : ObjectId("59eeba4e5f82df4555f2bfb5"), "name" : "Manju", "age" : 23, "place" : "Amaravati", "profession" : "Carpenter" }
{ "_id" : ObjectId("59eeba4e5f82df4555f2bfb6"), "name" : "Bharat", "age" : 24, "place" : "New York", "profession" : "Scientiest" }
{ "_id" : ObjectId("59eeba4e5f82df4555f2bfb7"), "name" : "Arya", "age" : 25, "profession" : "Teacher" }

Now, prepare a criteria to select a document.

> criteria={name:"Manju"}
{ "name" : "Manju" }

Verify the documents you select with the criteria

> db.people.find(criteria)
{ "_id" : ObjectId("59eeba4e5f82df4555f2bfb5"), "name" : "Manju", "age" : 23, "place" : "Amaravati", "profession" : "Carpenter" }

We shall prepare the update document as below

> update={name:"Manju",age:28,place:"Vizag"}
{ "name" : "Manju", "age" : 28, "place" : "Vizag" }

To update only the values you want to change, rather than mentioning all the values once again, use $set command. Next example demonstrates the usage of $set command.

Let the Options have their default value.

And execute the update command on the Collection.

> db.people.update(criteria,update)
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })

MongoDB has acknowledged that “nMatched” : 1 there has been one Document that matched the Criteria, and “nModified” : 1  has modified one document.

Verify the update by querying the collection with the criteria

> db.people.find(criteria)
{ "_id" : ObjectId("59eeba4e5f82df4555f2bfb5"), "name" : "Manju", "age" : 28, "place" : "Vizag" }

The details have been updated successfully.

Example 2 – Update multiple MongoDB Documents

In this example, we shall update multiple mongodb documents with the help of $set command in update document and option multi set to true.

We shall use following people  Collection in this Document Update Example and run the commands in Mongo Shell.

> db.people.find({})
{ "_id" : ObjectId("59eeba4e5f82df4555f2bfb2"), "name" : "Midhuna", "age" : 23, "place" : "Amaravati" }
{ "_id" : ObjectId("59eeba4e5f82df4555f2bfb3"), "name" : "Akhil", "age" : 24, "place" : "New York" }
{ "_id" : ObjectId("59eeba4e5f82df4555f2bfb4"), "name" : "Honey", "age" : 27, "profession" : "Docter" }
{ "_id" : ObjectId("59eeba4e5f82df4555f2bfb5"), "name" : "Manju", "age" : 28, "place" : "Vizag", "profession" : "Driver" }
{ "_id" : ObjectId("59eeba4e5f82df4555f2bfb6"), "name" : "Bharat", "age" : 24, "place" : "New York", "profession" : "Programmer" }
{ "_id" : ObjectId("59eeba4e5f82df4555f2bfb7"), "name" : "Arya", "age" : 25, "profession" : "Teacher" }

Now, prepare a criteria to select multiple MongoDB documents.

> criteria={place:"New York"}
{ "place" : "New York" }

> db.people.find(criteria).count()
2

There are multiple documents selected for the criteria.

We shall prepare the update document as below, including $set command

> update={$set:{bonus:250}}
{ "$set" : { "bonus" : 250 } }

To update only the values you want to change, rather than mentioning all the values once again, we used $set command.

We shall set multi option to true to update multiple MongoDB documents

> options={multi:true}
{ "multi" : true }

And execute the update command on the Collection.

> db.people.update(criteria,update,options)
WriteResult({ "nMatched" : 2, "nUpserted" : 0, "nModified" : 2 })

MongoDB has acknowledged that “nMatched” : 2 there has been two documents that matched the criteria, and “nModified” : 2  has modified all the documents that matched the criteria.

Verify the update by querying the document with the criteria

> db.people.find(criteria)
{ "_id" : ObjectId("59eeba4e5f82df4555f2bfb3"), "name" : "Akhil", "age" : 24, "place" : "New York", "bonus" : 250 }
{ "_id" : ObjectId("59eeba4e5f82df4555f2bfb6"), "name" : "Bharat", "age" : 24, "place" : "New York", "profession" : "Programmer", "bonus" : 250 }

The details have been updated successfully.

Conclusion

In this MongoDB Tutorial – MongoDB Update Document, we have learnt to update single or multiple MongoDB documents using update() method and $set command with the help of examples.