db.createView()
Creates a view as the result of the applying the specified aggregation pipeline to the source collection or view. Views act as read-only collections, and are computed on demand during read operations. You must create views in the same database as the source collection. MongoDB executes read operations on views as part of the underlying aggregation pipeline.
A view definition pipeline cannot include the $out or the $merge stage. This restriction also applies to embedded pipelines, such as pipelines used in $lookup or $facet stages.
This method is available in deployments hosted in the following environments:
MongoDB Atlas: The fully managed service for MongoDB deployments in the cloud
This command is supported in all MongoDB Atlas clusters. For information on Atlas support for all commands, see Unsupported Commands.
MongoDB Enterprise: The subscription-based, self-managed version of MongoDB
MongoDB Community: The source-available, free-to-use, and self-managed version of MongoDB
db.createView() has the following syntax:
db.createView(<view>, <source>, <pipeline>, <collation>)The method accepts the following parameters:
Parameter
Type
Description
view
string
The name of the view to create.
source
string
The name of the source collection or view from which to create the view. The name does not include the database name and implies the same database as the view to create; it is not the full namespace of the collection or view. You must create views in the same database as the source collection.
pipeline
array
An array that consists of the aggregation pipeline stage(s). db.createView() creates the view by applying the specified pipeline to the source collection or view.
A view definition pipeline cannot include the $out or the $merge stage. This restriction also applies to embedded pipelines, such as pipelines used in $lookup or $facet stages.
The view definition is public; i.e. db.getCollectionInfos() and explain operations on the view will include the pipeline that defines the view. As such, avoid referring directly to sensitive fields and values in view definitions.
collation
document
Optional. Specifies the default collation for the view.
Collation allows users to specify language-specific rules for string comparison, such as rules for lettercase and accent marks.
If the underlying source is a collection, the view does not inherit the collection's collation settings.
If no collation is specified, the view's default collation is the "simple" binary comparison collator.
If the underlying source is another view, the view must specify the same collation settings.
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.
The db.createView() method wraps the following create command operation:
db.runCommand( { create: <view>, viewOn: <source>, pipeline: <pipeline>, collation: <collation> } )Operations that list collections, such as db.getCollectionInfos() and db.getCollectionNames(), include views in their outputs.
The view definition is public; i.e. db.getCollectionInfos() and explain operations on the view will include the pipeline that defines the view. As such, avoid referring directly to sensitive fields and values in view definitions.
To see examples of creating a view, see the following pages:
To see behavioral details of views, see Behavior.
RetroSearch is an open source project built by @garambo | Open a GitHub Issue
Search and Browse the WWW like it's 1997 | Search results from DuckDuckGo
HTML:
3.2
| Encoding:
UTF-8
| Version:
0.7.4