listCollections

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Definition

Syntax
Command Fields
Behavior
Required Access
Output
Example
Learn More

Definition

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 information you can use to create a cursor on the collection.

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

Syntax

The command has the following syntax:

db.runCommand(
   {
     listCollections: 1,
     filter: <document>,
     nameOnly: <boolean>,
     authorizedCollections: <boolean>,
     comment: <any>
   }
)

Command Fields

The command can take the following optional fields:

Field	Type	Description
`filter`	document	Optional. A query expression to filter the list of collections. You can specify a query expression on any of the fields returned by `listCollections`.
`nameOnly`	boolean	Optional. A flag to indicate whether the command should return just the collection/view names and type or return both the name and other information. Returning just the name and type (`view` or `collection`) does not take collection-level locks whereas returning full collection information locks each collection in the database. The default value is `false`. Note 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 have `listCollections` 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 the `attr.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). New in version 4.4.

Behavior

Filter

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.

Locks

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.

Client Disconnection

Starting in MongoDB 4.2, if the client that issued listCollections disconnects before the operation completes, MongoDB marks listCollections for termination using killOp.

Replica Set Member State Restriction

Starting in MongoDB 4.4, 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.

In previous versions, the operations also run when the member is in STARTUP2. The operations wait until the member transitioned to RECOVERING.

Required Access

The listCollections command requires the listCollections 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 run db.getCollectionInfos() against the test database:

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

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

Users without the required read privilege can run listCollections when authorizedCollections and nameOnly are 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 following find privilege:

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

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

db.runCommand(
   {
       listCollections: 1.0,
       authorizedCollections: true,
       nameOnly: true
   }
)

The operation returns the name and type of the currentQuarter collection.

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
   }
)

`show collections`

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.

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:

Field	Type	Description
name	String	Name of the collection.
type	String	Type of data store. Returns `collection` for collections, `view` for views, and `timeseries` for time series collection.
options	Document	Collection options. These options correspond directly to the options available in `db.createCollection()`. For the descriptions on the options, see `db.createCollection()`.
info	Document	Lists 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.
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.

Example

List All Collections

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

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

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
}

Learn More

For collection options:

For collection information:

Back

killOp

listDatabases

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Definition

Syntax

Command Fields

Note

Behavior

Filter

Locks

Client Disconnection

Replica Set Member State Restriction

Required Access

show collections

Output

Example

List All Collections

Learn More

listCollections

`show collections`