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- db.collection.updateOne()
db.collection.updateOne()¶
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Definition¶
-
db.collection.updateOne(filter, update, options)¶ mongoShell MethodThis page documents the
mongoshell method, and does not refer to the MongoDB Node.js driver (or any other driver) method. For corresponding MongoDB driver API, refer to your specific MongoDB driver documentation instead.New in version 3.2.
Updates a single document within the collection based on the filter.
Syntax¶
The updateOne() method has the following syntax:
Parameters¶
The db.collection.updateOne() method takes the following
parameters:
| Parameter | Type | Description | ||||
|---|---|---|---|---|---|---|
| filter | document | The selection criteria for the update. The same query
selectors as in the Specify an empty document |
||||
| update | document or pipeline | The modifications to apply. Can be one of the following:
To update with a replacement document, see
|
||||
upsert |
boolean | Optional. When
To avoid multiple upserts, ensure that the Defaults to |
||||
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. |
||||
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. New in version 3.4. |
||||
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 Note The 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 arrayFilters for an Array Update Operations. New in version 3.6. |
||||
| hint | Document or string | Optional. A document or string that specifies the index to use to support the query predicate. The option can take an index specification document or the index name string. If you specify an index that does not exist, the operation errors. For an example, see Specify hint for Update Operations. New in version 4.2.1. |
Returns¶
The method returns a document that contains:
matchedCountcontaining the number of matched documentsmodifiedCountcontaining the number of modified documentsupsertedIdcontaining the_idfor the upserted document.- A boolean
acknowledgedastrueif the operation ran with write concern orfalseif write concern was disabled
Access Control¶
On deployments running with authorization, the
user must have access that includes the following privileges:
updateaction on the specified collection(s).findaction on the specified collection(s).insertaction on the specified collection(s) if the operation results in an upsert.
The built-in role readWrite provides the required
privileges.
Behavior¶
Updates a Single Document¶
db.collection.updateOne() finds the first document that
matches the filter and applies the specified
update modifications.
Update with an Update Operator Expressions Document¶
For the update specifications, the
db.collection.updateOne() method can accept a document that
only contains update operator expressions.
For example:
Update with an Aggregation Pipeline¶
Starting in MongoDB 4.2, the db.collection.updateOne() method
can accept an aggregation pipeline [ <stage1>, <stage2>, ... ] that
specifies the modifications to perform. The pipeline can consist of
the following stages:
$addFieldsand its alias$set$projectand its alias$unset$replaceRootand its alias$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:
Note
The $set and $unset used in the pipeline refers to the
aggregation stages $set and $unset
respectively, and not the update operators $set and $unset.
For examples, see Update with Aggregation Pipeline.
Upsert¶
If upsert: true and no documents match the filter,
db.collection.updateOne() creates a new
document based on the filter criteria and update modifications. See
Update with Upsert.
If you specify upsert: true on a sharded collection, you must
include the full shard key in the filter. For
additional db.collection.updateOne() behavior on a sharded
collection, see Sharded Collections.
Capped Collection¶
If an update operation changes the document size, the operation will fail.
Sharded Collections¶
upsert on a Sharded Collection¶
To use db.collection.updateOne() on a sharded collection:
- If you don’t specify
upsert: true, you must include an exact match on the_idfield or target a single shard (such as by including the shard key in the filter). - If you specify
upsert: true, the filter must include the shard key.
However, 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:
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. Before
MongoDB 4.2, 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.updateOne():
- 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.
See also upsert on a Sharded Collection.
Missing Shard Key¶
Starting in version 4.4, documents in a sharded collection can be
missing the shard key fields. To use
db.collection.updateOne() to set the document’s
missing shard key, you must run on a
mongos. Do not issue the operation directly on
the shard.
In addition, the following requirements also apply:
| Requirements | |
|---|---|
To set to null |
|
To set to a non-null value |
|
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:
Transactions¶
db.collection.updateOne() 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¶
Starting in MongoDB 4.4 with feature compatibility version
(fcv) "4.4", you can create collections and indexes
inside a multi-document transaction if the transaction is
not a cross-shard write transaction.
As such, for the feature compatibility version (fcv) is "4.4" or greater, db.collection.updateOne() with upsert:
true can be run against an existing collection or a non-existing
collection. If run against a non-existing collection, the operation
creates the collection.
If the feature compatibility version (fcv) is
"4.2" or less, the operation must be against an existing
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 using Update Operator Expressions¶
The restaurant collection contains the following documents:
The following operation updates a single document where
name: "Central Perk Cafe" with the violations field:
The operation returns:
If no matches were found, the operation instead returns:
Setting upsert: true would insert the document if no match was found. See
Update with Upsert
Update with Aggregation Pipeline¶
Starting in MongoDB 4.2, the db.collection.updateOne() can use
an aggregation pipeline for the update. The pipeline can consist of the
following stages:
$addFieldsand its alias$set$projectand its alias$unset$replaceRootand its alias$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).
Example 1¶
The following examples uses the aggregation pipeline to modify a field using the values of the other fields in the document.
Create a members collection with the following documents:
Assume that instead of separate misc1 and misc2 fields in the
first document, you want to gather these into a comments field,
like the second document. The following update operation uses an
aggregation pipeline to:
- add the new
commentsfield and set thelastUpdatefield. - remove the
misc1andmisc2fields for all documents in the collection.
Note
The $set and $unset used in the pipeline refers to the
aggregation stages $set and $unset
respectively, and not the update operators $set and $unset.
- First Stage
The
$setstage:- creates a new array field
commentswhose elements are the current content of themisc1andmisc2fields and - sets the field
lastUpdateto the value of the aggregation variableNOW. The aggregation variableNOWresolves to the current datetime value and remains the same throughout the pipeline. To access aggregation variables, prefix the variable with double dollar signs$$and enclose in quotes.
- creates a new array field
- Second Stage
- The
$unsetstage removes themisc1andmisc2fields.
After the command, the collection contains the following documents:
Example 2¶
The aggregation pipeline allows the update to perform conditional updates based on the current field values as well as use current field values to calculate a separate field value.
For example, create a students3 collection with the following documents:
The third document _id: 3 is missing the average and grade
fields. Using an aggregation pipeline, you can update the document with
the calculated grade average and letter grade.
Note
The $set used in the pipeline refers to the aggregation stage
$set, and not the update operators $set.
- First Stage
The
$setstage:- calculates a new field
averagebased on the average of thetestsfield. See$avgfor more information on the$avgaggregation operator and$truncfor more information on the$trunctruncate aggregation operator. - sets the field
lastUpdateto the value of the aggregation variableNOW. The aggregation variableNOWresolves to the current datetime value and remains the same throughout the pipeline. To access aggregation variables, prefix the variable with double dollar signs$$and enclose in quotes.
- calculates a new field
- Second Stage
- The
$setstage calculates a new fieldgradebased on theaveragefield calculated in the previous stage. See$switchfor more information on the$switchaggregation operator.
After the command, the collection contains the following documents:
See also
Update with Upsert¶
The restaurant collection contains the following documents:
The following operation attempts to update the document with
name : "Pizza Rat's Pizzaria", while upsert: true :
Since upsert:true the document is inserted based on the filter and
update criteria. The operation returns:
The collection now contains the following documents:
The name field was filled in using the filter criteria, while the
update operators were used to create the rest of the document.
The following operation updates the first document with violations that
are greater than 10:
The operation returns:
The collection now contains the following documents:
Since no documents matched the filter, and upsert was true,
updateOne inserted the document with a generated
_id and the update criteria only.
Update with Write Concern¶
Given a three member replica set, the following operation specifies a
w of majority, wtimeout of 100:
If the primary and at least one secondary acknowledge each write operation within 100 milliseconds, it returns:
If the acknowledgement takes longer than the wtimeout limit, the following
exception is thrown:
Changed in version 4.4.
The following table explains the possible values of
errInfo.writeConcern.provenance:
| Provenance | Description |
|---|---|
clientSupplied |
The write concern was specified in the application. |
customDefault |
The write concern originated from a custom defined
default value. See setDefaultRWConcern. |
getLastErrorDefaults |
The write concern originated from the replica set’s
settings.getLastErrorDefaults field. |
implicitDefault |
The write concern originated from the server in absence of all other write concern specifications. |
Specify Collation¶
New in version 3.4.
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:
The following operation includes the collation option:
Specify arrayFilters for an Array Update Operations¶
New in version 3.6.
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¶
Create a collection students with the following documents:
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.updateOne method:
The operation updates the grades field of a single document, and
after the operation, the collection has the following documents:
Update Specific Elements of an Array of Documents¶
Create a collection students2 with the following documents:
To modify the value of the mean field for all elements in the
grades array where the grade is greater than or equal to 85,
use the filtered positional operator $[<identifier>] with
the arrayFilters in the db.collection.updateOne method:
The operation updates the array of a single document, and after the operation, the collection has the following documents:
Specify hint for Update Operations¶
New in version 4.2.1.
Create a sample members collection with the following documents:
Create the following indexes on the collection:
The following update operation explicitly hints to use the index {
status: 1 }:
Note
If you specify an index that does not exist, the operation errors.
The update command returns the following:
To view the indexes used, you can use the $indexStats pipeline:
See also
To update multiple documents, see
db.collection.updateMany().