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Definition![](/zh-cn/docs/v5.3/assets/link.svg)
db.collection.findAndModify(document)
Important
mongosh Method
This is a
mongosh
method. This is not the documentation forNode.js
or other programming language specific driver methods.In most cases,
mongosh
methods work the same way as the legacymongo
shell methods. However, some legacy methods are unavailable inmongosh
.For the legacy
mongo
shell documentation, refer to the documentation for the corresponding MongoDB Server release:For MongoDB API drivers, refer to the language specific MongoDB driver documentation.
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. ThefindAndModify()
method is a shell helper around thefindAndModify
command.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>, 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:ParameterTypeDescriptionquery
documentOptional. The selection criteria for the modification. The
query
field employs the same query selectors as used in thedb.collection.find()
method. Although the query may match multiple documents,db.collection.findAndModify()
will only select one document to modify.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.
sort
documentOptional. Determines which document the operation modifies if the query selects multiple documents.
db.collection.findAndModify()
modifies the first document in the sort order specified by this argument.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
_id
field in your sort query.See Sort Consistency for more information.
remove
booleanMust specify either theremove
or theupdate
field. Removes the document specified in thequery
field. Set this totrue
to remove the selected document . The default isfalse
.update
document or arrayMust specify either the
remove
or theupdate
field. Performs an update of the selected document.If passed a document with update operator expressions,
db.collection.findAndModify()
performs the specified modification.If passed a replacement document
{ <field1>: <value1>, ...}
, thedb.collection.findAndModify()
performs a replacement.Starting in MongoDB 4.2, if passed an aggregation pipeline
[ <stage1>, <stage2>, ... ]
,db.collection.findAndModify()
modifies the document per the pipeline. The pipeline can consist of the following stages:$addFields
and its alias$set
$replaceRoot
and its alias$replaceWith
.
new
booleanOptional. Whentrue
, returns the modified document rather than the original. Thedb.collection.findAndModify()
method ignores thenew
option forremove
operations. The default isfalse
.fields
documentOptional. A subset of fields to return. The
fields
document specifies an inclusion of a field with1
, as in:fields: { <field1>: 1, <field2>: 1, ... }
.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
fields
Projection.upsert
booleanOptional. Used in conjunction with the
update
field.When
true
,findAndModify()
either:Creates a new document if no documents match the
query
. For more details see upsert behavior.Updates a single document that matches the
query
.
To avoid multiple upserts, ensure that the
query
field(s) are uniquely indexed. See Upsert with Unique Index for an example.Defaults to
false
, which does not insert a new document when no match is found.bypassDocumentValidation
booleanOptional. Enablesdb.collection.findAndModify()
to bypass document validation during the operation. This lets you update documents that do not meet the validation requirements.writeConcern
documentOptional. 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
integerOptional. Specifies a time limit in milliseconds for processing the operation.collation
documentOptional.
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:
collation: { locale: <string>, caseLevel: <boolean>, caseFirst: <string>, strength: <int>, numericOrdering: <boolean>, alternate: <string>, maxVariable: <string>, backwards: <boolean> } When specifying collation, the
locale
field is mandatory; all other collation fields are optional. For descriptions of the fields, see Collation Document.If the collation is unspecified but the collection has a default collation (see
db.createCollection()
), the operation uses the collation specified for the collection.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
arrayOptional. 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
$[<identifier>]
filtered positional operator to define an identifier, which you then reference in the array filter documents. You cannot have an array filter document for an identifier if the identifier is not included in the update document.Note
The
<identifier>
must begin with a lowercase letter and contain only alphanumeric characters.You can include the same identifier multiple times in the update document; however, for each distinct identifier (
$[identifier]
) in the update document, you must specify exactly one corresponding array filter document. That is, you cannot specify multiple array filter documents for the same identifier. For example, if the update statement includes the identifierx
(possibly multiple times), you cannot specify the following forarrayFilters
that includes 2 separate filter documents forx
:// INVALID [ { "x.a": { $gt: 85 } }, { "x.b": { $gt: 80 } } ] However, you can specify compound conditions on the same identifier in a single filter document, such as in the following examples:
// Example 1 [ { $or: [{"x.a": {$gt: 85}}, {"x.b": {$gt: 80}}] } ] // Example 2 [ { $and: [{"x.a": {$gt: 85}}, {"x.b": {$gt: 80}}] } ] // Example 3 [ { "x.a": { $gt: 85 }, "x.b": { $gt: 80 } } ] For examples, see Specify
arrayFilters
for an Array Update Operations.Note
arrayFilters
is not available for updates that use an aggregation pipeline.documentOptional.
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:
{ <variable_name_1>: <expression_1>, ..., <variable_name_n>: <expression_n> } 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 (
$$
) together with your variable name in the form$$<variable_name>
. For example:$$targetTotal
.Note
To use a variable to filter results, you must access the variable within the
$expr
operator.For a complete example using
let
and variables, see Use Variables inlet
.New in version 5.0.
Return Data![](/zh-cn/docs/v5.3/assets/link.svg)
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![](/zh-cn/docs/v5.3/assets/link.svg)
fields
Projection![](/zh-cn/docs/v5.3/assets/link.svg)
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. Non-zero integers are also
treated as true . |
<field>: <0 or false> | Specifies the exclusion of a field. |
"<field>.$": <1 or true> | |
<field>: <array projection> | Using the array projection operators $elemMatch ,
$slice , specifies the array element(s) to include,
thereby excluding those elements that do not meet the
expressions. (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. For example,
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![](/zh-cn/docs/v5.3/assets/link.svg)
For fields in an embedded documents, you can specify the field using either:
dot notation; e.g.
"field.nestedfield": <value>
nested form; e.g.
{ field: { nestedfield: <value> } }
(Starting in MongoDB 4.4)
_id
Field Projection![](/zh-cn/docs/v5.3/assets/link.svg)
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![](/zh-cn/docs/v5.3/assets/link.svg)
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![](/zh-cn/docs/v5.3/assets/link.svg)
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![](/zh-cn/docs/v5.3/assets/link.svg)
When using findAndModify
against a sharded collection, the
query
must contain an equality condition on shard key.
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![](/zh-cn/docs/v5.3/assets/link.svg)
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![](/zh-cn/docs/v5.3/assets/link.svg)
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![](/zh-cn/docs/v5.3/assets/link.svg)
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![](/zh-cn/docs/v5.3/assets/link.svg)
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![](/zh-cn/docs/v5.3/assets/link.svg)
db.collection.findAndModify()
can be used inside multi-document transactions.
Important
In most cases, multi-document transaction incurs a greater performance cost over single document writes, and the availability of multi-document 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 multi-document transactions.
For additional transactions usage considerations (such as runtime limit and oplog size limit), see also Production Considerations.
Upsert within Transactions![](/zh-cn/docs/v5.3/assets/link.svg)
Starting in MongoDB 4.4, you can create collections and indexes inside a multi-document transaction if the transaction is not a cross-shard write transaction.
Specifically, in MongoDB 4.4 and greater, 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.
In MongoDB 4.2 and earlier, the operation must be run on an existing collection.
Tip
Write Concerns and Transactions![](/zh-cn/docs/v5.3/assets/link.svg)
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![](/zh-cn/docs/v5.3/assets/link.svg)
Update and Return![](/zh-cn/docs/v5.3/assets/link.svg)
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![](/zh-cn/docs/v5.3/assets/link.svg)
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![](/zh-cn/docs/v5.3/assets/link.svg)
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![](/zh-cn/docs/v5.3/assets/link.svg)
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![](/zh-cn/docs/v5.3/assets/link.svg)
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![](/zh-cn/docs/v5.3/assets/link.svg)
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![](/zh-cn/docs/v5.3/assets/link.svg)
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![](/zh-cn/docs/v5.3/assets/link.svg)
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![](/zh-cn/docs/v5.3/assets/link.svg)
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
![](/zh-cn/docs/v5.3/assets/link.svg)
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" } } )