db.collection.findAndModify()
Definition
db.collection.findAndModify(document)
Important
mongosh Method
This page documents a
mongosh
method. This is not the documentation for database commands or language-specific drivers, such as Node.js.For the database command, see the
findAndModify
command.For MongoDB API drivers, refer to the language-specific MongoDB driver documentation.
For the legacy
mongo
shell documentation, refer to the documentation for the corresponding MongoDB Server release:Modifies and returns a single document. By default, the returned document does not include the modifications made on the update. To return the document with the modifications made on the update, use the
new
option.
Compatibility
You can use db.collection.findAndModify()
for deployments hosted in the following
environments:
MongoDB Atlas: The fully managed service for MongoDB deployments in the cloud
MongoDB Enterprise: The subscription-based, self-managed version of MongoDB
MongoDB Community: The source-available, free-to-use, and self-managed version of MongoDB
Syntax
Changed in version 5.0.
The findAndModify()
method has the following
form:
db.collection.findAndModify({ query: <document>, sort: <document>, remove: <boolean>, update: <document or aggregation pipeline>, // Changed in MongoDB 4.2 new: <boolean>, fields: <document>, upsert: <boolean>, bypassDocumentValidation: <boolean>, writeConcern: <document>, maxTimeMS: <integer>, collation: <document>, arrayFilters: [ <filterdocument1>, ... ], let: <document> // Added in MongoDB 5.0 });
The db.collection.findAndModify()
method takes a document
parameter with the following embedded document fields:
Parameter | Type | Description | ||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
query | document | Optional. The selection criteria for the modification. The If unspecified, defaults to an empty document. Starting in MongoDB 4.2 (and 4.0.12+, 3.6.14+, and 3.4.23+), the operation errors if the query argument is not a document. | ||||||||||||||||||
| document | Optional. Determines which document the operation modifies if the query selects
multiple documents. Starting in MongoDB 4.2 (and 4.0.12+, 3.6.14+, and 3.4.23+), the operation errors if the sort argument is not a document. MongoDB does not store documents in a collection in a particular order. When sorting on a field which contains duplicate values, documents containing those values may be returned in any order. If consistent sort order is desired, include at least one field in your
sort that contains unique values. The easiest way to guarantee this is
to include the See Sort Consistency for more information. | ||||||||||||||||||
remove | boolean | Must specify either the remove or the update field. Removes
the document specified in the query field. Set this to true
to remove the selected document . The default is false . | ||||||||||||||||||
update | document or array | Must specify either the
| ||||||||||||||||||
new | boolean | Optional. When true , returns the modified document rather than the original.
The default is false . | ||||||||||||||||||
fields | document | Optional. A subset of fields to return. The Starting in MongoDB 4.2 (and 4.0.12+, 3.6.14+, and 3.4.23+), the operation errors if the fields argument is not a document. For more information on projection, see | ||||||||||||||||||
upsert | boolean | Optional. Used in conjunction with the When
To avoid multiple upserts, ensure that the
Defaults to | ||||||||||||||||||
bypassDocumentValidation | boolean | Optional. Enables db.collection.findAndModify() to bypass document validation
during the operation. This lets you update documents that do not
meet the validation requirements. | ||||||||||||||||||
writeConcern | document | Optional. A document expressing the write concern. Omit to use the default write concern. Do not explicitly set the write concern for the operation if run in a transaction. To use write concern with transactions, see Transactions and Write Concern. | ||||||||||||||||||
maxTimeMS | non-negative integer | Optional. Specifies a time limit in milliseconds.
If you do not specify a value for MongoDB terminates operations that exceed their allotted time limit
using the same mechanism as | ||||||||||||||||||
collation | document | Optional. Specifies the collation to use for the operation. Collation allows users to specify language-specific rules for string comparison, such as rules for lettercase and accent marks. The collation option has the following syntax:
When specifying collation, the If the collation is unspecified but the collection has a
default collation (see If no collation is specified for the collection or for the operations, MongoDB uses the simple binary comparison used in prior versions for string comparisons. You cannot specify multiple collations for an operation. For example, you cannot specify different collations per field, or if performing a find with a sort, you cannot use one collation for the find and another for the sort. | ||||||||||||||||||
arrayFilters | array | Optional. An array of filter documents that determine which array elements to modify for an update operation on an array field. In the update document, use the NoteThe You can include the same identifier multiple times in the update
document; however, for each distinct identifier (
However, you can specify compound conditions on the same identifier in a single filter document, such as in the following examples:
For examples, see Specify Note
| ||||||||||||||||||
document | Optional. Specifies a document with a list of variables. This allows you to improve command readability by separating the variables from the query text. The document syntax is:
The variable is set to the value returned by the expression, and cannot be changed afterwards. To access the value of a variable in the command, use the double
dollar sign prefix ( NoteTo use a variable to filter results, you must access the variable
within the For a complete example using New in version 5.0. |
Return Data
For remove operations, if the query matches a document,
findAndModify()
returns the removed document.
If the query does not match a document to remove,
findAndModify()
returns null
.
For update operations, findAndModify()
returns
one of the following:
If the
new
parameter is not set or isfalse
:the pre-modification document if the query matches a document;
otherwise,
null
.
If
new
istrue
:the modified document if the query returns a match;
the inserted document if
upsert: true
and no document matches the query;otherwise,
null
.
Behavior
fields
Projection
Important
Language Consistency
Starting in MongoDB 4.4, as part of making
find()
and
findAndModify()
projection consistent with
aggregation's $project
stage,
The
find()
andfindAndModify()
projection can accept aggregation expressions and syntax.MongoDB enforces additional restrictions with regards to projections. See Projection Restrictions for details.
The fields
option takes a document in the following form:
{ field1: <value>, field2: <value> ... }
Projection | Description |
---|---|
<field>: <1 or true> | Specifies the inclusion of a field. If you specify a non-zero
integer for the projection value, the operation treats the
value as true . |
<field>: <0 or false> | Specifies the exclusion of a field. |
"<field>.$": <1 or true> | |
<field>: <array projection> | Uses the array projection operators ( Not available for views. |
<field>: <aggregation expression> | Specifies the value of the projected field. Starting in MongoDB 4.4, with the use of aggregation expressions and syntax, including the use of literals and aggregation variables, you can project new fields or project existing fields with new values.
In versions 4.2 and earlier, any specification value (with
the exception of the previously unsupported document
value) is treated as either New in version 4.4. |
Embedded Field Specification
For fields in an embedded documents, you can specify the field using either:
dot notation, for example
"field.nestedfield": <value>
nested form, for example
{ field: { nestedfield: <value> } }
(Starting in MongoDB 4.4)
_id
Field Projection
The _id
field is included in the returned documents by default unless
you explicitly specify _id: 0
in the projection to suppress the field.
Inclusion or Exclusion
A projection
cannot contain both include and exclude
specifications, with the exception of the _id
field:
In projections that explicitly include fields, the
_id
field is the only field that you can explicitly exclude.In projections that explicitly excludes fields, the
_id
field is the only field that you can explicitly include; however, the_id
field is included by default.
For more information on projection, see also:
Upsert with Unique Index
When using the upsert: true
option with the findOneAndUpdate()
method, and not using a unique index on the query field(s), multiple
instances of a findOneAndUpdate()
operation with similar query
field(s) could result in duplicate documents being inserted in
certain circumstances.
Consider an example where no document with the name Andy
exists
and multiple clients issue the following command at roughly the same
time:
db.people.findAndModify( { query: { name: "Andy" }, update: { $inc: { score: 1 } }, upsert: true } )
If all findOneAndUpdate()
operations finish the query phase
before any client successfully inserts data, and there is no
unique index on the name
field, each
findOneAndUpdate()
operation may result in an insert, creating multiple
documents with name: Andy
.
To ensure that only one such document is created, and the other
findOneAndUpdate()
operations update this new document instead, create a
unique index on the name
field. This
guarantees that only one document with name: Andy
is permitted
in the collection.
With this unique index in place, the multiple findOneAndUpdate()
operations
now exhibit the following behavior:
Exactly one
findOneAndUpdate()
operation will successfully insert a new document.All other
findOneAndUpdate()
operations will update the newly-inserted document, incrementing thescore
value.
Sharded Collections
To use findAndModify
on a sharded collection:
If you only target one shard, you can use a partial shard key in the
query
field or,You can provide an equality condition on a full shard key in the
query
field.
Starting in version 4.4, documents in a sharded collection can be
missing the shard key fields. To target a
document that is missing the shard key, you can use the null
equality match in conjunction with another filter condition
(such as on the _id
field). For example:
{ _id: <value>, <shardkeyfield>: null } // _id of the document missing shard key
Shard Key Modification
Starting in MongoDB 4.2, you can update a document's shard key value
unless the shard key field is the immutable _id
field. In
MongoDB 4.2 and earlier, a document's shard key field value is
immutable.
Warning
Starting in version 4.4, documents in sharded collections can be missing the shard key fields. Take precaution to avoid accidentally removing the shard key when changing a document's shard key value.
To modify the existing shard key value with
db.collection.findAndModify()
:
You must run on a
mongos
. Do not issue the operation directly on the shard.You must run either in a transaction or as a retryable write.
You must include an equality filter on the full shard key.
Missing Shard Key
Starting in version 4.4, documents in a sharded collection can be
missing the shard key fields. To use
db.collection.findAndModify()
to set the document's
missing shard key:
You must run on a
mongos
. Do not issue the operation directly on the shard.You must run either in a transaction or as a retryable write if the new shard key value is not
null
.You must include an equality filter on the full shard key.
Tip
Since a missing key value is returned as part of a null equality
match, to avoid updating a null-valued key, include additional
query conditions (such as on the _id
field) as appropriate.
See also:
Document Validation
The db.collection.findAndModify()
method adds support for the
bypassDocumentValidation
option, which lets you bypass
document validation when
inserting or updating documents in a collection with validation
rules.
Comparisons with the update
Method
When updating a document, db.collection.findAndModify()
and the
updateOne()
method operate differently:
If multiple documents match the update criteria, for
db.collection.findAndModify()
, you can specify asort
to provide some measure of control on which document to update.updateOne()
updates the first document that matches.By default,
db.collection.findAndModify()
returns the pre-modified version of the document. To obtain the updated document, use thenew
option.The
updateOne()
method returns aWriteResult()
object that contains the status of the operation.To return the updated document, use the
find()
method. However, other updates may have modified the document between your update and the document retrieval. Also, if the update modified only a single document but multiple documents matched, you will need to use additional logic to identify the updated document.
When modifying a single document, both db.collection.findAndModify()
and the
updateOne()
method atomically update the
document. See Atomicity and Transactions for more
details about interactions and order of operations of these methods.
Transactions
db.collection.findAndModify()
can be used inside distributed transactions.
Important
In most cases, a distributed transaction incurs a greater performance cost over single document writes, and the availability of distributed transactions should not be a replacement for effective schema design. For many scenarios, the denormalized data model (embedded documents and arrays) will continue to be optimal for your data and use cases. That is, for many scenarios, modeling your data appropriately will minimize the need for distributed transactions.
For additional transactions usage considerations (such as runtime limit and oplog size limit), see also Production Considerations.
Upsert within Transactions
You can create collections and indexes inside a distributed transaction if the transaction is not a cross-shard write transaction.
db.collection.findAndModify()
with upsert: true
can be run on an existing
collection or a non-existing collection. If run on a non-existing
collection, the operation creates the collection.
Write Concerns and Transactions
Do not explicitly set the write concern for the operation if run in a transaction. To use write concern with transactions, see Transactions and Write Concern.
Examples
Update and Return
The following method updates and returns an existing document in the people collection where the document matches the query criteria:
db.people.findAndModify({ query: { name: "Tom", state: "active", rating: { $gt: 10 } }, sort: { rating: 1 }, update: { $inc: { score: 1 } } })
This method performs the following actions:
The
query
finds a document in thepeople
collection where thename
field has the valueTom
, thestate
field has the valueactive
and therating
field has a valuegreater than
10.The
sort
orders the results of the query in ascending order. If multiple documents meet thequery
condition, the method will select for modification the first document as ordered by thissort
.The update
increments
the value of thescore
field by 1.The method returns the original (i.e. pre-modification) document selected for this update:
{ "_id" : ObjectId("50f1e2c99beb36a0f45c6453"), "name" : "Tom", "state" : "active", "rating" : 100, "score" : 5 } To return the modified document, add the
new:true
option to the method.If no document matched the
query
condition, the method returnsnull
.
Upsert
The following method includes the upsert: true
option for the
update
operation to either update a matching document or, if no
matching document exists, create a new document:
db.people.findAndModify({ query: { name: "Gus", state: "active", rating: 100 }, sort: { rating: 1 }, update: { $inc: { score: 1 } }, upsert: true })
If the method finds a matching document, the method performs an update.
If the method does not find a matching document, the method creates
a new document. Because the method included the sort
option, it
returns an empty document { }
as the original (pre-modification)
document:
{ }
If the method did not include a sort
option, the method returns
null
.
null
Return New Document
The following method includes both the upsert: true
option and the
new:true
option. The method either updates a matching document and
returns the updated document or, if no matching document exists,
inserts a document and returns the newly inserted document in the
value
field.
In the following example, no document in the people
collection
matches the query
condition:
db.people.findAndModify({ query: { name: "Pascal", state: "active", rating: 25 }, sort: { rating: 1 }, update: { $inc: { score: 1 } }, upsert: true, new: true })
The method returns the newly inserted document:
{ "_id" : ObjectId("50f49ad6444c11ac2448a5d6"), "name" : "Pascal", "rating" : 25, "score" : 1, "state" : "active" }
Sort and Remove
By including a sort
specification on the rating
field, the
following example removes from the people
collection a single
document with the state
value of active
and the lowest
rating
among the matching documents:
db.people.findAndModify( { query: { state: "active" }, sort: { rating: 1 }, remove: true } )
The method returns the deleted document:
{ "_id" : ObjectId("52fba867ab5fdca1299674ad"), "name" : "XYZ123", "score" : 1, "state" : "active", "rating" : 3 }
Specify Collation
Collation allows users to specify language-specific rules for string comparison, such as rules for lettercase and accent marks.
A collection myColl
has the following documents:
{ _id: 1, category: "café", status: "A" } { _id: 2, category: "cafe", status: "a" } { _id: 3, category: "cafE", status: "a" }
The following operation includes the collation option:
db.myColl.findAndModify({ query: { category: "cafe", status: "a" }, sort: { category: 1 }, update: { $set: { status: "Updated" } }, collation: { locale: "fr", strength: 1 } });
The operation returns the following document:
{ "_id" : 1, "category" : "café", "status" : "A" }
Specify arrayFilters
for an Array Update Operations
Note
arrayFilters
is not available for updates that use an
aggregation pipeline.
Starting in MongoDB 3.6, when updating an array field, you can
specify arrayFilters
that determine which array elements to
update.
Update Elements Match arrayFilters
Criteria
Note
arrayFilters
is not available for updates that use an
aggregation pipeline.
Create a collection students
with the following documents:
db.students.insertMany( [ { "_id" : 1, "grades" : [ 95, 92, 90 ] }, { "_id" : 2, "grades" : [ 98, 100, 102 ] }, { "_id" : 3, "grades" : [ 95, 110, 100 ] } ] )
To modify all elements that are greater than or equal to 100
in the
grades
array, use the filtered positional operator
$[<identifier>]
with the arrayFilters
option in the
db.collection.findAndModify()
method:
db.students.findAndModify({ query: { grades: { $gte: 100 } }, update: { $set: { "grades.$[element]" : 100 } }, arrayFilters: [ { "element": { $gte: 100 } } ] })
The operation updates the grades
field for a single document, and
after the operation, the collection has the following documents:
{ "_id" : 1, "grades" : [ 95, 92, 90 ] } { "_id" : 2, "grades" : [ 98, 100, 100 ] } { "_id" : 3, "grades" : [ 95, 110, 100 ] }
Update Specific Elements of an Array of Documents
Note
arrayFilters
is not available for updates that use an
aggregation pipeline.
Create a collection students2
with the following documents:
db.students2.insertMany( [ { "_id" : 1, "grades" : [ { "grade" : 80, "mean" : 75, "std" : 6 }, { "grade" : 85, "mean" : 90, "std" : 4 }, { "grade" : 85, "mean" : 85, "std" : 6 } ] }, { "_id" : 2, "grades" : [ { "grade" : 90, "mean" : 75, "std" : 6 }, { "grade" : 87, "mean" : 90, "std" : 3 }, { "grade" : 85, "mean" : 85, "std" : 4 } ] } ] )
The following operation finds a document where the _id
field equals
1
and uses the filtered positional operator $[<identifier>]
with
the arrayFilters
to modify the mean
for all elements in the
grades
array where the grade is greater than or equal to 85
.
db.students2.findAndModify({ query: { _id : 1 }, update: { $set: { "grades.$[elem].mean" : 100 } }, arrayFilters: [ { "elem.grade": { $gte: 85 } } ] })
The operation updates the grades
field for a single document, and after the
operation, the collection has the following documents:
{ "_id" : 1, "grades" : [ { "grade" : 80, "mean" : 75, "std" : 6 }, { "grade" : 85, "mean" : 100, "std" : 4 }, { "grade" : 85, "mean" : 100, "std" : 6 } ] } { "_id" : 2, "grades" : [ { "grade" : 90, "mean" : 75, "std" : 6 }, { "grade" : 87, "mean" : 90, "std" : 3 }, { "grade" : 85, "mean" : 85, "std" : 4 } ] }
Use an Aggregation Pipeline for Updates
Starting in MongoDB 4.2, db.collection.findAndModify()
can
accept an aggregation pipeline for the update. The pipeline can consist
of the following stages:
$addFields
and its alias$set
$replaceRoot
and its alias$replaceWith
.
Using the aggregation pipeline allows for a more expressive update statement, such as expressing conditional updates based on current field values or updating one field using the value of another field(s).
For example, create a collection students2
with the following documents:
db.students2.insertMany( [ { "_id" : 1, "grades" : [ { "grade" : 80, "mean" : 75, "std" : 6 }, { "grade" : 85, "mean" : 90, "std" : 4 }, { "grade" : 85, "mean" : 85, "std" : 6 } ] }, { "_id" : 2, "grades" : [ { "grade" : 90, "mean" : 75, "std" : 6 }, { "grade" : 87, "mean" : 90, "std" : 3 }, { "grade" : 85, "mean" : 85, "std" : 4 } ] } ] )
The following operation finds a document where the _id
field equals
1
and uses an aggregation pipeline to calculate a new field
total
from the grades
field:
db.students2.findAndModify( { query: { "_id" : 1 }, update: [ { $set: { "total" : { $sum: "$grades.grade" } } } ], // The $set stage is an alias for ``$addFields`` stage new: true } )
Note
The operation returns the updated document:
{ "_id" : 1, "grades" : [ { "grade" : 80, "mean" : 75, "std" : 6 }, { "grade" : 85, "mean" : 90, "std" : 4 }, { "grade" : 85, "mean" : 85, "std" : 6 } ], "total" : 250 }
Use Variables in let
New in version 5.0.
To define variables that you can access elsewhere in the command, use the let option.
Note
To filter results using a variable, you must access the variable
within the $expr
operator.
Create a collection cakeFlavors
:
db.cakeFlavors.insertMany( [ { _id: 1, flavor: "chocolate" }, { _id: 2, flavor: "strawberry" }, { _id: 3, flavor: "cherry" } ] )
The following example defines a targetFlavor
variable in let
and
uses the variable to change the cake flavor from cherry to orange:
db.cakeFlavors.findAndModify( { query: { $expr: { $eq: [ "$flavor", "$$targetFlavor" ] } }, update: { flavor: "orange" }, let: { targetFlavor: "cherry" } } )
User Roles and Document Updates
Starting in MongoDB 7.0, you can use the new USER_ROLES
system variable to return user roles.
The example in this section shows updates to fields in a collection
containing medical information. The example reads the current user roles
from the USER_ROLES
system variable and only performs the updates if
the user has a specific role.
To use a system variable, add $$
to the start of the variable name.
Specify the USER_ROLES
system variable as $$USER_ROLES
.
The example creates these users:
James
with aBilling
role.Michelle
with aProvider
role.
Perform the following steps to create the roles, users, and collection:
Create the roles
Create roles named Billing
and Provider
with the required
privileges and resources.
Run:
db.createRole( { role: "Billing", privileges: [ { resource: { db: "test", collection: "medicalView" }, actions: [ "find" ] } ], roles: [ ] } ) db.createRole( { role: "Provider", privileges: [ { resource: { db: "test", collection: "medicalView" }, actions: [ "find" ] } ], roles: [ ] } )
Log in as as Michelle
, who has the Provider
role, and perform an
update:
Perform update
Run:
// Attempt to find and modify document db.medical.findAndModify( { query: { $and: [ { // Only update the document for Mary Smith patientName: { $eq: "Mary Smith" } }, { // User must have the Provider role to perform the update $expr: { $ne: [ { $setIntersection: [ [ "Provider" ], "$$USER_ROLES.role" ] }, [] ] } } ] }, // Update document update: { patientName: "Mary Smith", diagnosisCode: "ACH 03", creditCard: "6541-7534-9637-3456" } } )
The previous example uses $setIntersection
to return
documents where the intersection between the "Provider"
string and
the user roles from $$USER_ROLES.role
is not empty. Michelle
has
the Provider
role, so the update is performed.
Next, log in as as James
, who does not have the Provider
role,
and attempt to perform the same update:
Attempt to perform update
Run:
// Attempt to find and modify document db.medical.findAndModify( { query: { $and: [ { // Only update the document for Mary Smith patientName: { $eq: "Mary Smith" } }, { // User must have the Provider role to perform the update $expr: { $ne: [ { $setIntersection: [ [ "Provider" ], "$$USER_ROLES.role" ] }, [] ] } } ] }, // Update document update: { patientName: "Mary Smith", diagnosisCode: "ACH 03", creditCard: "6541-7534-9637-3456" } } )
The previous example does not update any documents.