listCollections (original) (raw)

listCollections

Retrieves information, including the names and creation options, for the collections and views in a database.

The listCollections command returns a document that contains an unsorted list of all collections and views in the database. You can use the returned document to create a cursor on the collection.

mongosh provides the db.getCollectionInfos()and the db.getCollectionNames() helper methods.

This command is available in deployments hosted in the following environments:

MongoDB Atlas: The fully managed service for MongoDB deployments in the cloud

Note

This command is supported in all MongoDB Atlas clusters. For information on Atlas support for all commands, seeUnsupported 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

The command has the following syntax:


db.runCommand(

   {

     listCollections: 1,

     filter: <document>,

     nameOnly: <boolean>,

     authorizedCollections: <boolean>,

     comment: <any>

   }

)

The command can take the following optional fields:

Field	Type	Description
filter	document	Optional. A query predicate to filter the list of collections.You can specify a query predicate on any of the fields returned by listCollections.
nameOnly	boolean	Optional. A flag to indicate whether the command should return just the name and type (view, collection, or timeseries) or return both the name and other information.The default value is false.When nameOnly is true, your filter expression can only filter based on a collection's name and type. No other fields are available.
authorizedCollections	boolean	Optional. A flag, when set to true and used with nameOnly: true, that allows a user without the required privilege (i.e.listCollections action on the database) to run the command when access control is enforced.When both authorizedCollections and nameOnly options are set to true, the command returns only those collections for which the user has privileges. For example, if a user has find action on specific collections, the command returns only those collections; or, if a user has find or any other action, on the database resource, the command lists all collections in the database.The default value is false. That is, the user must havelistCollections action on the database to run the command.For a user who has listCollections action on the database, this option has no effect since the user has privileges to list the collections in the database.When used without nameOnly: true, this option has no effect. That is, the user must have the required privileges to run the command when access control is enforced. Otherwise, the user is unauthorized to run the command.
comment	any	Optional. A user-provided comment to attach to this command. Once set, this comment appears alongside records of this command in the following locations:mongod log messages, in theattr.command.cursor.comment field.Database profiler output, in the command.comment field.currentOp output, in the command.comment field.A comment can be any valid BSON type(string, integer, object, array, etc).Any comment set on a listCollections command is inherited by any subsequent getMore commands run on thelistCollections cursor.

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

listCollections lock behavior:

Earlier than MongoDB 5.0, listCollections takes an intent shared lock lock on each collection in the database when listCollections holds an intent shared lock on the database.
Starting in MongoDB 5.0, listCollections doesn't take an intent shared lock on a collection or database. listCollections isn't blocked by operations holding an exclusive write lock on a collection.

To learn about locks, see FAQ: Concurrency.

Starting in MongoDB 4.2, if the client that issued listCollectionsdisconnects before the operation completes, MongoDB marks listCollectionsfor termination using killOp.

To run on a replica set member, listCollections operations require the member to be in PRIMARY or SECONDARY state. If the member is in another state, such as STARTUP2, the operation errors.

The listCollections command requires thelistCollections action when access control is enforced. Users must have privileges that grant the listCollections action on the database to run listCollections.

For example, the following command grants the privilege to rundb.getCollectionInfos() against the test database:


{ resource: { db: "test", collection: "" }, actions: [ "listCollections" ] }

The built-in role read provides the privilege to runlistCollections for a specific database.

Users without the required read privilege can runlistCollections when authorizedCollections and nameOnlyare both set to true. In this case, the command returns the names and types for collection(s) where the user has privileges.

For example, consider a user with a role that grants the followingfind privilege:


{ resource: { db: "sales", collection: "currentQuarter" }, actions: [ "find" ] }

The user can run listCollections if authorizedCollectionsand nameOnly are both set to true.


db.runCommand(

   {

       listCollections: 1.0,

       authorizedCollections: true,

       nameOnly: true

   }

)

The operation returns the name and type of the currentQuartercollection.

However, the following operations return an error if the user does not have the required access authorization:


db.runCommand(

   {

       listCollections: 1.0,

       authorizedCollections: true

   }

)

db.runCommand(

   {

       listCollections: 1.0,

       nameOnly: true

   }

)

The mongosh method show collections is similar to:


db.runCommand(

   {

       listCollections: 1.0,

       authorizedCollections: true,

       nameOnly: true

   }

)

For users with the required access, show collections lists the non-system collections for the database.
For users without the required access, show collections lists only the collections for which the users has privileges.

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:

Field	Type	Description
name	String	Name of the collection.
type	String	Type of data store. Returns collection forcollections, view forviews, and timeseries fortime series collection.
options	Document	Collection options.These options correspond directly to the options available indb.createCollection(). For the descriptions on the options, see db.createCollection().
info	Document	Lists the following fields related to the collection:readOnlyboolean. If true the data store is read only.uuidUUID. Once established, the collection UUID does not change. The collection UUID remains the same across replica set members and shards in a sharded cluster.
idIndex	Document	Provides information on the _id index for the collection.

listCollections.ok

The return value for the command. A value of 1 indicates success.

The music database contains three collections, motorhead,taylorSwift, and ramones.

To list the collections in the database, you can use the built-inmongosh command, show collections.

The output is:


motorhead

ramones

taylorSwift

To get a similar list with the listCollections collections command, use the nameOnly option.


db.runCommand(

   {

      listCollections: 1.0,

      nameOnly: true

   }

)

The output is:


{

  cursor: {

    id: Long("0"),

    ns: 'music.$cmd.listCollections',

    firstBatch: [

      { name: 'motorhead', type: 'collection' },

      { name: 'taylorSwift', type: 'collection' },

      { name: 'ramones', type: 'collection' }

    ]

  },

  ok: 1

}

To get more detailed information, remove the nameOnly option.


db.runCommand(

   {

      listCollections: 1.0

   }

)

The output is:


{

  cursor: {

    id: Long("0"),

    ns: 'music.$cmd.listCollections',

    firstBatch: [

      {

        name: 'motorhead',

        type: 'collection',

        options: {},

        info: {

          readOnly: false,

          uuid: new UUID("09ef1858-2831-47d2-a3a7-9a29a9cfeb94")

        },

        idIndex: { v: 2, key: { _id: 1 }, name: '_id_' }

      },

      {

        name: 'taylorSwift',

        type: 'collection',

        options: {},

        info: {

          readOnly: false,

          uuid: new UUID("6c46c8b9-4999-4213-bcef-9a36b0cff228")

        },

        idIndex: { v: 2, key: { _id: 1 }, name: '_id_' }

      },

      {

        name: 'ramones',

        type: 'collection',

        options: {},

        info: {

          readOnly: false,

          uuid: new UUID("7e1925ba-f2f9-4e42-90e4-8cafd434a6c4")

        },

        idIndex: { v: 2, key: { _id: 1 }, name: '_id_' }

      }

    ]

  },

  ok: 1

}

For collection options:

For collection information: