listCollections

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New in version 3.0.0.

Definition

  • listCollections
    • Retrieve information, i.e. the name and options, about the collections and views in a database. Specifically, the command returns a document that contains information with which to create a cursor to the collection information. The mongo shell provides the db.getCollectionInfos() and the db.getCollectionNames() helper methods.

The command has the following form:

{ listCollections: 1, filter: <document> }

The listCollections command can take the following optional field:

FieldTypeDescription
filterdocumentOptional. A query expression to filter the list of collections.
You can specify a query expression on any of the fields returned by listCollections .

Behavior

Use a filter to limit the results of listCollections. You can specify a filter on any of the fields returned in the listCollections result set.

Output

  • listCollections. cursor
    • A document that contains information with which to create a cursor to documents that contain collection names and options. The cursor information includes the cursor id, the full namespace for the command, as well as the first batch of results. Each document in the batch output contains the following fields:
FieldTypeDescription
nameStringName of the collection.
typeStringType of data store. Returns collection for collections and view for views.
optionsDocumentCollection options.
These options correspond directly to the options available in db.createCollection(), with the exception of the "options.flags" . The "options.flags" corresponds to the usePowerOf2Sizes and the noPadding options in the db.createCollection() method:
0 corresponds to usePowerOf2Sizes flag set to false and noPadding flag set to false .
1 corresponds to usePowerOf2Sizes flag set to true and noPadding flag set to false .
2 corresponds to usePowerOf2Sizes flag set to false and noPadding flag set to true .
3 corresponds to usePowerOf2Sizes flag set to true and noPadding flag set to true .
> [!NOTE|label:Note]
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> MongoDB 3.0 ignores the usePowerOf2Sizes flag. See collMod and db.createCollection() for more information.
>
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For the descriptions on the options, see db.createCollection().
infoDocumentLists the following fields related to the collection:
readOnly
boolean . If true the data store is read only.
uuid
UUID. Once established, the collection UUID does not change. The collection UUID remains the same across replica set members and shards in a sharded cluster.
New in version 3.6.
idIndexDocumentProvides information on the _id index for the collection.
  • listCollections. ok
    • The return value for the command. A value of 1 indicates success.

Required Access

The user executing the command requires either find privileges on the system.namespaces collection or the listCollections privilege action. At a minimum, the read built-in role provide the requisite permissions.

Example

List All Collections

The following example uses the db.getCollectionInfos() helper to return information for all collections in the records database:

use records
db.getCollectionInfos();