Because MongoDB creates a collection implicitly when the collection is first referenced in a command, this method is used primarily for creating new collections that use specific options. For example, you use
to create a:New collection that uses document validation.
is a wrapper around the database command
The method has the following prototype form:
Note
Starting in MongoDB 4.2
MongoDB removes the MMAPv1 storage engine and the MMAPv1 specific options
changeStreamPreAndPostImages: { |
enabled: <boolean> |
} |
changeStreamPreAndPostImages: { |
enabled: <boolean> |
} |
changeStreamPreAndPostImages: { |
enabled: <boolean> |
} |
db.createCollection( <name>, |
{ |
capped: <boolean>, |
timeseries: { // Added in MongoDB 5.0 |
timeField: <string>, // required for time series collections |
metaField: <string>, |
granularity: <string> |
}, |
expireAfterSeconds: <number>, |
clusteredIndex: <document>, // Added in MongoDB 5.3 |
changeStreamPreAndPostImages: <document>, // Added in MongoDB 6.0 |
size: <number>, |
max: <number>, |
storageEngine: <document>, |
validator: <document>, |
validationLevel: <string>, |
validationAction: <string>, |
indexOptionDefaults: <document>, |
viewOn: <string>, |
pipeline: <pipeline>, |
collation: <document>, |
writeConcern: <document> |
} |
) |
The method has the following parameters:
Parameter
Type
Description
9changeStreamPreAndPostImages: { enabled: <boolean> }
string
The name of the collection to create. See
0{ <storage-engine-name>: <options> }
document
Optional. Configuration options for creating a: Capped collection Custered collection View
The
{ <storage-engine-name>: <options> } |
Field
Type
Description
2{ <storage-engine-name>: <options> }
boolean
Optional. To create a , specify
3. If you specify { <storage-engine-name>: <options> }
3, you must also set a maximum size in the { <storage-engine-name>: <options> }
5 field.{ <storage-engine-name>: <options> }
6{ <storage-engine-name>: <options> }
string
Required when creating a . The name of the field which contains the date in each time series document. Documents in a time series collection must have a valid BSON date as the value for the
7.{ <storage-engine-name>: <options> }
8{ <storage-engine-name>: <options> }
string
Optional. The name of the field which contains metadata in each time series document. The metadata in the specified field should be data that is used to label a unique series of documents. The metadata should rarely, if ever, change. The name of the specified field may not be
9 or the same as the { <storage-engine-name>: <options> }
6. The field can be of any type except array.{ <storage-engine-name>: <options> }
1{ <storage-engine-name>: <options> }
string
Optional. Possible values are
2 (default), { <storage-engine-name>: <options> }
3, and { <storage-engine-name>: <options> }
4. Set the granularity to the value that is the closest match to the time span between consecutive incoming measurements. Setting the { <storage-engine-name>: <options> }
5 parameter improves performance by optimizing how data in the time series collection is stored internally.{ <storage-engine-name>: <options> }
number
Optional. Specifies the seconds after which documents in a or expire. MongoDB deletes expired documents automatically. For clustered collections, the documents are deleted automatically based on the clustered index key
9 and the values must be date types. See { <storage-engine-name>: <options> }
document
Starting in MongoDB 5.3, you can create a collection with a . Collections created with a clustered index are called clustered collections. See
7 has the following syntax:{ <storage-engine-name>: <options> }
clusteredIndex: { |
key: { <string> }, |
unique: <boolean>, |
name: <string> |
} |
Field
Description
8{ <storage-engine-name>: <options> }
Required. The clustered index key field. Must be set to
9. The default value for the { <storage-engine-name>: <options> }
9 field is an automatically generated unique , but you can set your own { <storage-engine-name>: <options> }
1collation: { locale: <string>, caseLevel: <boolean>, caseFirst: <string>, strength: <int>, numericOrdering: <boolean>, alternate: <string>, maxVariable: <string>, backwards: <boolean> }
Required. Must be set to
3. A unique index indicates the collection will not accept inserted or updated documents where the clustered index key value matches an existing value in the index.{ <storage-engine-name>: <options> }
9changeStreamPreAndPostImages: { enabled: <boolean> }
Optional. A name that uniquely identifies the clustered index.
New in version 5.3.
document
Optional. Starting in MongoDB 6.0, you can use to output the version of a document before and after changes (the document pre- and post-images): The pre-image is the document before it was replaced, updated, or deleted. There is no pre-image for an inserted document.
The post-image is the document after it was inserted, replaced, or updated. There is no post-image for a deleted document.
Enable
collation: { |
locale: <string>, |
caseLevel: <boolean>, |
caseFirst: <string>, |
strength: <int>, |
numericOrdering: <boolean>, |
alternate: <string>, |
maxVariable: <string>, |
backwards: <boolean> |
} |
collation: { |
locale: <string>, |
caseLevel: <boolean>, |
caseFirst: <string>, |
strength: <int>, |
numericOrdering: <boolean>, |
alternate: <string>, |
maxVariable: <string>, |
backwards: <boolean> |
} |
changeStreamPreAndPostImages: { |
enabled: <boolean> |
} |
9collation: { locale: <string>, caseLevel: <boolean>, caseFirst: <string>, strength: <int>, numericOrdering: <boolean>, alternate: <string>, maxVariable: <string>, backwards: <boolean> }
Description
3{ <storage-engine-name>: <options> }
Enables change stream pre- and post-images for a collection.
1db.createCollection("log", { capped : true, size : 5242880, max : 5000 } )
Disables change stream pre- and post-images for a collection.
For complete examples with the change stream output, see
For a example on this page, see
New in version 6.0.
5{ <storage-engine-name>: <options> }
number
Optional. Specify a maximum size in bytes for a capped collection. Once a capped collection reaches its maximum size, MongoDB removes the older documents to make space for the new documents. The
5 field is required for capped collections and ignored for other collections.{ <storage-engine-name>: <options> }
5db.createCollection("log", { capped : true, size : 5242880, max : 5000 } )
number
Optional. The maximum number of documents allowed in the capped collection. The
5 limit takes precedence over this limit. If a capped collection reaches the { <storage-engine-name>: <options> }
5 limit before it reaches the maximum number of documents, MongoDB removes old documents. If you prefer to use the { <storage-engine-name>: <options> }
5 limit, ensure that the db.createCollection("log", { capped : true, size : 5242880, max : 5000 } )
5 limit, which is required for a capped collection, is sufficient to contain the maximum number of documents.{ <storage-engine-name>: <options> }
0db.createCollection( "weather24h", { timeseries: { timeField: "timestamp", metaField: "data", granularity: "hours" }, expireAfterSeconds: 86400 } )
document
Optional. Available for the WiredTiger storage engine only. Allows users to specify configuration to the storage engine on a per-collection basis when creating a collection. The value of the
0 option should take the following form:db.createCollection( "weather24h", { timeseries: { timeField: "timestamp", metaField: "data", granularity: "hours" }, expireAfterSeconds: 86400 } )
{ <storage-engine-name>: <options> } |
Storage engine configuration specified when creating collections are validated and logged to the during replication to support replica sets with members that use different storage engines.
Tip
See also:
2db.createCollection( "weather24h", { timeseries: { timeField: "timestamp", metaField: "data", granularity: "hours" }, expireAfterSeconds: 86400 } )
document
Optional. Allows users to specify validation rules or expressions for the collection. For more information, see Schema Validation. The
2 option takes a document that specifies the validation rules or expressions. You can specify the expressions using the same operators as the with the exception of , , , and db.createCollection( "weather24h", { timeseries: { timeField: "timestamp", metaField: "data", granularity: "hours" }, expireAfterSeconds: 86400 } )
To learn how to create a collection with schema validation, see
8db.createCollection( "weather24h", { timeseries: { timeField: "timestamp", metaField: "data", granularity: "hours" }, expireAfterSeconds: 86400 } )
string
Optional. Determines how strictly MongoDB applies the validation rules to existing documents during an update. Description No validation for inserts or updates. Default Apply validation rules to all inserts and all updates. Apply validation rules to inserts and to updates on existing valid documents. Do not apply rules to updates on existing invalid documents. To see an example that uses
8db.createCollection( "weather24h", { timeseries: { timeField: "timestamp", metaField: "data", granularity: "hours" }, expireAfterSeconds: 86400 } )
0db.createCollection( "stocks", { clusteredIndex: { "key": { _id: 1 }, "unique": true, "name": "stocks clustered key" } } )
1db.createCollection( "stocks", { clusteredIndex: { "key": { _id: 1 }, "unique": true, "name": "stocks clustered key" } } )
2db.createCollection( "stocks", { clusteredIndex: { "key": { _id: 1 }, "unique": true, "name": "stocks clustered key" } } )
8, see db.createCollection( "weather24h", { timeseries: { timeField: "timestamp", metaField: "data", granularity: "hours" }, expireAfterSeconds: 86400 } )
4db.createCollection( "stocks", { clusteredIndex: { "key": { _id: 1 }, "unique": true, "name": "stocks clustered key" } } )
string
Optional. Determines whether to
5 on invalid documents or just db.createCollection( "stocks", { clusteredIndex: { "key": { _id: 1 }, "unique": true, "name": "stocks clustered key" } } )
6 about the violations but allow invalid documents to be inserted.db.createCollection( "stocks", { clusteredIndex: { "key": { _id: 1 }, "unique": true, "name": "stocks clustered key" } } )
Important
Validation of documents only applies to those documents as determined by the
db.createCollection( |
"weather24h", |
{ |
timeseries: { |
timeField: "timestamp", |
metaField: "data", |
granularity: "hours" |
}, |
expireAfterSeconds: 86400 |
} |
) |
To see an example that uses
db.createCollection( |
"stocks", |
{ clusteredIndex: { "key": { _id: 1 }, "unique": true, "name": "stocks clustered key" } } |
) |
9db.createCollection( "stocks", { clusteredIndex: { "key": { _id: 1 }, "unique": true, "name": "stocks clustered key" } } )
document
Optional. Allows users to specify a default configuration for indexes when creating a collection. The
9 option accepts a db.createCollection( "stocks", { clusteredIndex: { "key": { _id: 1 }, "unique": true, "name": "stocks clustered key" } } )
0 document, which should take the following form:db.createCollection( "weather24h", { timeseries: { timeField: "timestamp", metaField: "data", granularity: "hours" }, expireAfterSeconds: 86400 } )
{ <storage-engine-name>: <options> } |
Storage engine configuration specified when creating indexes are validated and logged to the during replication to support replica sets with members that use different storage engines.
2db.createCollection( "temperatureSensor", { changeStreamPreAndPostImages: { enabled: true } } );
string
The name of the source collection or view from which to create the view. The name is not the full namespace of the collection or view; i.e. does not include the database name and implies the same database as the view to create. You must create views in the same database as the source collection. See also
4db.createCollection( "temperatureSensor", { changeStreamPreAndPostImages: { enabled: true } } );
array
An array that consists of the . creates the view by applying the specified
4 to the db.createCollection( "temperatureSensor", { changeStreamPreAndPostImages: { enabled: true } } );
2 collection or view.db.createCollection( "temperatureSensor", { changeStreamPreAndPostImages: { enabled: true } } );
A view definition
db.createCollection( |
"temperatureSensor", |
{ changeStreamPreAndPostImages: { enabled: true } } |
); |
The view definition is public; i.e. and
clusteredIndex: { |
key: { <string> }, |
unique: <boolean>, |
name: <string> |
} |
See also
06clusteredIndex: { key: { <string> }, unique: <boolean>, name: <string> }
document
Specifies the default for the collection. 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
clusteredIndex: { |
key: { <string> }, |
unique: <boolean>, |
name: <string> |
} |
If you specify a collation at the collection level:
Indexes on that collection will be created with that collation unless the index creation operation explicitly specify a different collation.
Operations on that collection use the collection's default collation unless they explicitly specify a different collation.
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.
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.
For a collection, you can only specify the collation during the collection creation. Once set, you cannot modify the collection's default collation.
For an example, see
08clusteredIndex: { key: { <string> }, unique: <boolean>, name: <string> }
document
Optional. A document that expresses the write concern for the operation. Omit to use the default write concern. When issued on a sharded cluster, converts the write concern of the command and its helper to
Access Control
If the deployment enforces , requires the following privileges:
Task
Required Privileges
Create a non-capped collection
on the database, or on the collection to create
Create a
for the collection on the database
Create a
on the database. However, if the user has the on the database and on the view to create, the user must also have the following additional permissions: on the source collection or view. on any other collections or views referenced in the
4, if any.db.createCollection( "temperatureSensor", { changeStreamPreAndPostImages: { enabled: true } } );
A user with the built in role on the database has the required privileges to run the listed operations. Either create a user with the required role or
Behavior
Resource Locking
Changed in version 4.2.
obtains an exclusive lock on the specified collection or view for the duration of the operation. All subsequent operations on the collection must wait until releases the lock. typically holds this lock for a short time.
Creating a view requires obtaining an additional exclusive lock on the
clusteredIndex: { |
key: { <string> }, |
unique: <boolean>, |
name: <string> |
} |
Transactions
Changed in version 4.4.
Starting in MongoDB 4.4, you can create collections and indexes inside a if the transaction is
not a cross-shard write transaction.To use in a transaction, the transaction must use read concern . If you specify a read concern level other than , the transaction fails.
Tip
See also:
Examples
Create a Capped Collection
Capped collections have maximum size or document counts that prevent them from growing beyond maximum thresholds. All capped collections must specify a maximum size and may also specify a maximum document count. MongoDB removes older documents if a collection reaches the maximum size limit before it reaches the maximum document count. Consider the following example:
db.createCollection("log", { capped : true, size : 5242880, max : 5000 } ) |
This command creates a collection named
clusteredIndex: { |
key: { <string> }, |
unique: <boolean>, |
name: <string> |
} |
See Capped Collections for more information about capped collections.
Create a Time Series Collection
To create a that captures weather data for the past 24 hours, issue this command:
db.createCollection( |
"weather24h", |
{ |
timeseries: { |
timeField: "timestamp", |
metaField: "data", |
granularity: "hours" |
}, |
expireAfterSeconds: 86400 |
} |
) |
Create a Clustered Collection
The following example adds a named
clusteredIndex: { |
key: { <string> }, |
unique: <boolean>, |
name: <string> |
} |
db.createCollection( |
"stocks", |
{ clusteredIndex: { "key": { _id: 1 }, "unique": true, "name": "stocks clustered key" } } |
) |
In the example, specifies:
35, which sets the clustered index key to theclusteredIndex: { key: { <string> }, unique: <boolean>, name: <string> }
9 field.{ <storage-engine-name>: <options> }
37, which indicates the clustered index key value must be unique.clusteredIndex: { key: { <string> }, unique: <boolean>, name: <string> }
38, which sets the clustered index name.clusteredIndex: { key: { <string> }, unique: <boolean>, name: <string> }
Create a Collection with Change Stream Pre- and Post-Images for Documents
Starting in MongoDB 6.0, you can use to output the version of a document before and after changes (the document pre- and post-images):
The pre-image is the document before it was replaced, updated, or deleted. There is no pre-image for an inserted document.
The post-image is the document after it was inserted, replaced, or updated. There is no post-image for a deleted document.
Enable
4 for a collection using , , orcollation: { locale: <string>, caseLevel: <boolean>, caseFirst: <string>, strength: <int>, numericOrdering: <boolean>, alternate: <string>, maxVariable: <string>, backwards: <boolean> }
The following example creates a collection that has enabled:
db.createCollection( |
"temperatureSensor", |
{ changeStreamPreAndPostImages: { enabled: true } } |
); |
Pre- and post-images are not available for a if the images were:
Not enabled on the collection at the time of a document update or delete operation.
Removed after the pre- and post-image retention time set in
43.clusteredIndex: { key: { <string> }, unique: <boolean>, name: <string> } The following example sets
43 toclusteredIndex: { key: { <string> }, unique: <boolean>, name: <string> }
45 seconds:clusteredIndex: { key: { <string> }, unique: <boolean>, name: <string> }
0clusteredIndex: { key: { <string> }, unique: <boolean>, name: <string> } The following example returns the current
46 settings, includingclusteredIndex: { key: { <string> }, unique: <boolean>, name: <string> }
43:clusteredIndex: { key: { <string> }, unique: <boolean>, name: <string> }
1clusteredIndex: { key: { <string> }, unique: <boolean>, name: <string> } Setting
43 toclusteredIndex: { key: { <string> }, unique: <boolean>, name: <string> }
49 uses the default retention policy: pre- and post-images are retained until the corresponding change stream events are removed from theclusteredIndex: { key: { <string> }, unique: <boolean>, name: <string> } If a change stream event is removed from the oplog, then the corresponding pre- and post-images are also deleted regardless of the
43 pre- and post-image retention time.clusteredIndex: { key: { <string> }, unique: <boolean>, name: <string> }
Additional considerations:
Enabling pre- and post-images consumes storage space and adds processing time. Only enable pre- and post-images if you need them.
Limit the change stream event size to less than 16 megabytes. To limit the event size, you can:
Limit the document size to 8 megabytes. You can request pre- and post-images simultaneously in the if other change stream event fields like
51 are not large.clusteredIndex: { key: { <string> }, unique: <boolean>, name: <string> } Request only post-images in the change stream output for documents up to 16 megabytes if other change stream event fields like
51 are not large.clusteredIndex: { key: { <string> }, unique: <boolean>, name: <string> } Request only pre-images in the change stream output for documents up to 16 megabytes if:
document updates affect only a small fraction of the document structure or content, and
do not cause a
53 change event. AclusteredIndex: { key: { <string> }, unique: <boolean>, name: <string> }
53 event always includes the post-image.clusteredIndex: { key: { <string> }, unique: <boolean>, name: <string> }
To request a pre-image, you set
55 toclusteredIndex: { key: { <string> }, unique: <boolean>, name: <string> }
56 orclusteredIndex: { key: { <string> }, unique: <boolean>, name: <string> }
57 in . To request a post-image, you setclusteredIndex: { key: { <string> }, unique: <boolean>, name: <string> }
59 using the same method.clusteredIndex: { key: { <string> }, unique: <boolean>, name: <string> } Pre-images are written to the
60 collection.clusteredIndex: { key: { <string> }, unique: <boolean>, name: <string> } The
60 collection may become large. To limit the collection size, you can setclusteredIndex: { key: { <string> }, unique: <boolean>, name: <string> }
43 time for the pre-images as shown earlier.clusteredIndex: { key: { <string> }, unique: <boolean>, name: <string> } Pre-images are removed asynchronously by a background process.
Important
Backward-Incompatible Feature
Starting in MongoDB 6.0, if you are using document pre- and post-images for , you must disable for each collection using the command before you can downgrade to an earlier MongoDB version.
Tip
See also:
For change stream events and output, see
To watch a collection for changes, see
For complete examples with the change stream output, see
Specify Collation
Collation allows users to specify language-specific rules for string comparison, such as rules for lettercase and accent marks.
You can specify at the collection or level. For example, the following operation creates a collection, specifying a collation for the collection (See for descriptions of the collation fields):
clusteredIndex: { |
key: { <string> }, |
unique: <boolean>, |
name: <string> |
} |
This collation will be used by indexes and operations that support collation unless they explicitly specify a different collation. For example, insert the following documents into
clusteredIndex: { |
key: { <string> }, |
unique: <boolean>, |
name: <string> |
} |
clusteredIndex: { |
key: { <string> }, |
unique: <boolean>, |
name: <string> |
} |
The following operation uses the collection's collation:
clusteredIndex: { |
key: { <string> }, |
unique: <boolean>, |
name: <string> |
} |
The operation returns documents in the following order:
clusteredIndex: { |
key: { <string> }, |
unique: <boolean>, |
name: <string> |
} |
The same operation on a collection that uses simple binary collation (i.e. no specific collation set) returns documents in the following order:
clusteredIndex: { |
key: { <string> }, |
unique: <boolean>, |
name: <string> |
} |
Tip
See also:
Specify Storage Engine Options
You can specify collection-specific storage engine configuration options when you create a collection with . Consider the following operation: