Update Multiple Documents using updateMany() in MongoDB
Learn how to update multiple documents using the updateMany()
method in MongoDB.
MongoDB provides the following methods to update existing documents in a collection:
- db.collection.updateOne() - Modifies a single document in a collection.
- db.collection.updateMany() - Modifies one or more documents in a collection.
In most cases, it is recommended to use the updateMany()
method than the updateOne()
method.
db.collection.updateMany()
Use the db.<collection>.updateMany()
method to update multiple documents that matches with the specified filter criteria in a collection.
Syntax:
db.collection.updateMany(filter, document, options)
Parameters:
- filter: The selection criteria for the update, same as find() method.
- document: A document or pipeline that contains modifications to apply.
- options: Optional. May contains options for update behavior. It includes upsert, writeConcern, collation, etc.
In the above syntax, db
points to the current database, <collection>
points is an existing collection name.
To demonstrate the update operation, insert the following sample documents in the employees
collection.
db.employees.insertMany([
{
_id:1,
firstName: "John",
lastName: "King",
email: "[email protected]",
salary: 5000
},
{
_id:2,
firstName: "Sachin",
lastName: "T",
email: "[email protected]",
salary: 8000
},
{
_id:3,
firstName: "James",
lastName: "Bond",
email: "[email protected]",
salary: 7500
},
{
_id:4,
firstName: "Steve",
lastName: "J",
email: "[email protected]",
salary: 7000
},
{
_id:5,
firstName: "Kapil",
lastName: "D",
email: "[email protected]",
salary: 4500
},
{
_id:6,
firstName: "Amitabh",
lastName: "B",
email: "[email protected]",
salary: 7000
}
])
The following modifies matching documents using the updateMany()
method in employees
collection.
db.employees.updateMany({ salary:7000 }, { $set: { salary:8500 }})
{
acknowledged: true,
insertedId: null,
matchedCount: 2,
modifiedCount: 2,
upsertedCount: 0
}
In the above example, the first parameter is the filter criteria specified as a document, { salary:7000 }
indicates that find documents whose salary
are 7000
. The second parameter is used to specify fields and values to be modified on the matching document in the {<update-operator>: { field: value, field:value,... }}
format. Use the update operator to specify an action to perform. Here we want to set the value of fields, so use $set
operator to specify fields and updated values in {field:updated-value}
format.{ $set: {salary:8500}
modifies the salary
fields of all matching documents to 8500
.
In the output, matchedCount
indicates the number of documents that matched with the criteria, and modifiedCount
indicates the number of documents updated.
Now, check whether it has updated a value or not using the find()
method shown below.
db.employees.find()
[
{
_id: 1,
firstName: 'John',
lastName: 'King',
email: '[email protected]',
salary: 5000
},
{
_id: 2,
firstName: 'Sachin',
lastName: 'T',
email: '[email protected]',
salary: 8000
},
{
_id: 3,
firstName: 'James',
lastName: 'Bond',
email: '[email protected]',
salary: 7500
},
{
_id: 4,
firstName: 'Steve',
lastName: 'J',
email: '[email protected]',
salary: 8500
},
{
_id: 5,
firstName: 'Kapil',
lastName: 'D',
email: '[email protected]',
salary: 4500
},
{
_id: 6,
firstName: 'Amitabh',
lastName: 'B',
email: '[email protected]',
salary: 8500
}
]
The updateMany()
method adds the specified field if it does not exist in a matching document. For example, the following will add the location
field.
db.employees.updateMany({firstName:"Steve"}, { $set: {location: "USA"}})
{
acknowledged: true,
insertedId: null,
matchedCount: 1,
modifiedCount: 1,
upsertedCount: 0
}
Execute the following find()
method to see the updated data.
db.employees.find({firstName:"Steve"})
{
_id:4,
firstName: "Steve",
lastName: "J",
email: "[email protected]",
salary: 8500,
location:"USA"
}
If you specify an empty filter criteria {}
, then it will update all the documents. The following will update or add location
field in all documents.
db.employees.updateMany({}, { $set: {location: "USA"}})
{
acknowledged: true,
insertedId: null,
matchedCount: 6,
modifiedCount: 6,
upsertedCount: 0
}
Use the $inc
update operator to increase the value of the field by the specified amount. The following increases the salary
by 500
whose salary is 8500
.
db.employees.updateMany({salary:8500}, { $inc: {salary: 500}})
{
acknowledged: true,
insertedId: null,
matchedCount: 2,
modifiedCount: 2,
upsertedCount: 0
}
Update Multiple Fields
You can also specify multiple fields to update. The following updates email
and lastName
fields.
db.employees.updateMany({_id:2}, { $set: {lastName:"Tendulkar", email:"[email protected]"}})
{
acknowledged: true,
insertedId: null,
matchedCount: 1,
modifiedCount: 1,
upsertedCount: 0
}
Execute the following find()
method to see the updated data.
db.employees.find({_id:2})
{
_id:2,
firstName: "Sachin",
lastName: "Tendulkar",
email: "[email protected]",
salary: 8000
}
The updateMany()
method does not update any documents if no matching documents found. For example, the following will not update any documents.
db.employees.updateMany({salary:100}, { $set: {salary:200}})
{
acknowledged: true,
insertedId: null,
matchedCount: 0,
modifiedCount: 0,
upsertedCount: 0
}
Upsert - Add if not Exist
Specify {upsert:true}
as a third parameter in the UpdateMany()
method. The upsert:true
adds a new document if the matching document does not found.
db.employees.updateMany({firstName:"Heer"}, { $set: {lastName:"Patel", salary:2000}})
{
acknowledged: true,
insertedId: ObjectId("6172a2e9ce7d5ca09d6ab082"),
matchedCount: 0,
modifiedCount: 0,
upsertedCount: 1
}
In the above example, MongoDB adds a new document with new _id
, because it cannot find a document with the firstName:"Heer"
.
Update Operators
The following table lists the update operators which can be used with the updateOne()
and updateMany()
methods.
Method | Description |
---|---|
$currentDate | Sets the value of a field to current date, either as a Date or a Timestamp. |
$inc | Increments the value of the field by the specified amount. |
$min | Only updates the field if the specified value is less than the existing field value. |
$max | Only updates the field if the specified value is greater than the existing field value. |
$mul | Multiplies the value of the field by the specified amount. |
$rename | Renames a field. |
$set | Sets the value of a field in a document. |
$setOnInsert | Sets the value of a field if an update results in an insert of a document. Has no effect on update operations that modify existing documents. |
$unset | Removes the specified field from a document. |
Visit Update Operators on MongoDB documentation.