MongoDB’s update() and save() methods are used to update document into a collection. The update() method updates the values in the existing document while the save() method replaces the existing document with the document passed in the save() method.
MongoDB Update() Method
The update() method updates the values in the existing document.
Syntax
The basic syntax of the update() method is as follows −
>db.COLLECTION_NAME.update(SELECTION_CRITERIA, UPDATED_DATA)
Example
Consider the mycol collection has the following data.
{ "_id" : ObjectId(5983548781331adf45ec5), "title":"MongoDB Overview"}
{ "_id" : ObjectId(5983548781331adf45ec6), "title":"NoSQL Overview"}
{ "_id" : ObjectId(5983548781331adf45ec7), "title":"adglob Overview"}
The following example will set the new title ‘New MongoDB Tutorial’ of the documents whose title is ‘MongoDB Overview’.
>db.mycol.update({'title':'MongoDB Overview'},{$set:{'title':'New MongoDB Tutorial'}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
>db.mycol.find()
{ "_id" : ObjectId(5983548781331adf45ec5), "title":"New MongoDB Tutorial"}
{ "_id" : ObjectId(5983548781331adf45ec6), "title":"NoSQL Overview"}
{ "_id" : ObjectId(5983548781331adf45ec7), "title":"adglob Overview"}
>
By default, MongoDB will update only a single document. To update multiple documents, you need to set a parameter ‘multi’ to true.
>db.mycol.update({'title':'MongoDB Overview'},
{$set:{'title':'New MongoDB Tutorial'}},{multi:true})
MongoDB Save() Method
The save() method replaces the existing document with the new document passed in the save() method.
Syntax
The basic syntax of the MongoDB save() method is shown below −
>db.COLLECTION_NAME.save({_id:ObjectId(),NEW_DATA})
Example
The following example will replace the document with the _id ‘5983548781331adf45ec5’.
>db.mycol.save(
{
"_id" : ObjectId("507f191e810c19729de860ea"),
"title":"adglobs New Topic",
"by":"adglob"
}
)
WriteResult({
"nMatched" : 0,
"nUpserted" : 1,
"nModified" : 0,
"_id" : ObjectId("507f191e810c19729de860ea")
})
>db.mycol.find()
{ "_id" : ObjectId("507f191e810c19729de860e6"), "title":"Adglob New Topic",
"by":"Adglob"}
{ "_id" : ObjectId("507f191e810c19729de860e6"), "title":"NoSQL Overview"}
{ "_id" : ObjectId("507f191e810c19729de860e6"), "title":"Adglob Overview"}
>
MongoDB findOneAndUpdate() method
The findOneAndUpdate() method updates the values in the existing document.
Syntax
The basic syntax of the findOneAndUpdate() method is as follows −
>db.COLLECTION_NAME.findOneAndUpdate(SELECTIOIN_CRITERIA, UPDATED_DATA)
Example
Assume we have created a collection named empDetails and inserted three documents in it as shown below −
> db.empDetails.insertMany(
[
{
First_Name: "Radhika",
Last_Name: "Sharma",
Age: "26",
e_mail: "radhika_sharma.123@gmail.com",
phone: "9000012345"
},
{
First_Name: "Rachel",
Last_Name: "Christopher",
Age: "27",
e_mail: "Rachel_Christopher.123@gmail.com",
phone: "9000054321"
},
{
First_Name: "Fathima",
Last_Name: "Sheik",
Age: "24",
e_mail: "Fathima_Sheik.123@gmail.com",
phone: "9000054321"
}
]
)
Following example updates the age and email values of the document with name ‘Radhika’.
> db.empDetails.findOneAndUpdate(
{First_Name: 'Radhika'},
{ $set: { Age: '30',e_mail: 'radhika_newemail@gmail.com'}}
)
{
"_id" : ObjectId("5dd6636870fb13eec3963bf5"),
"First_Name" : "Radhika",
"Last_Name" : "Sharma",
"Age" : "30",
"e_mail" : "radhika_newemail@gmail.com",
"phone" : "9000012345"
}
MongoDB updateOne() method
This method updates a single document that matches the given filter.
Syntax
The basic syntax of updateOne() method is as follows −
>db.COLLECTION_NAME.updateOne(<filter>, <update>)
Example
> db.empDetails.updateOne(
{First_Name: 'Radhika'},
{ $set: { Age: '30',e_mail: 'radhika_newemail@gmail.com'}}
)
{ "acknowledged" : true, "matchedCount" : 1, "modifiedCount" : 0 }
>
MongoDB updateMany() method
The updateMany() method updates all the documents that match the given filter.
Syntax
The basic syntax of updateMany() method is as follows −
>db.COLLECTION_NAME.update(<filter>, <update>)
Example
> db.empDetails.updateMany(
{Age:{ $gt: "25" }},
{ $set: { Age: '00'}}
)
{ "acknowledged" : true, "matchedCount" : 2, "modifiedCount" : 2 }
You can see the updated values if you retrieve the contents of the document using the find method as shown below −
> db.empDetails.find()
{ "_id" : ObjectId("5dd6636870fb13eec3963bf5"), "First_Name" : "Radhika", "Last_Name" : "Sharma", "Age" : "00", "e_mail" : "radhika_newemail@gmail.com", "phone" : "9000012345" }
{ "_id" : ObjectId("5dd6636870fb13eec3963bf6"), "First_Name" : "Rachel", "Last_Name" : "Christopher", "Age" : "00", "e_mail" : "Rachel_Christopher.123@gmail.com", "phone" : "9000054321" }
{ "_id" : ObjectId("5dd6636870fb13eec3963bf7"), "First_Name" : "Fathima", "Last_Name" : "Sheik", "Age" : "24", "e_mail" : "Fathima_Sheik.123@gmail.com", "phone" : "9000054321" }
>
