Key

A unique identifier for an entity. If a key's partition ID or any of its path kinds or names are reserved/read-only, the key is reserved/read-only. A reserved/read-only key is forbidden in certain documented contexts.

JSON representation
{
  "partitionId": {
    object(PartitionId)
  },
  "path": [
    {
      object(PathElement)
    }
  ],
}
Fields
partitionId

object(PartitionId)

Entities are partitioned into subsets, currently identified by a project ID and namespace ID. Queries are scoped to a single partition.

path[]

object(PathElement)

The entity path. An entity path consists of one or more elements composed of a kind and a string or numerical identifier, which identify entities. The first element identifies a root entity, the second element identifies a child of the root entity, the third element identifies a child of the second entity, and so forth. The entities identified by all prefixes of the path are called the element's ancestors.

An entity path is always fully complete: all of the entity's ancestors are required to be in the path along with the entity identifier itself. The only exception is that in some documented cases, the identifier in the last path element (for the entity) itself may be omitted. For example, the last path element of the key of Mutation.insert may have no identifier.

A path can never be empty, and a path can have at most 100 elements.

PathElement

A (kind, ID/name) pair used to construct a key path.

If either name or ID is set, the element is complete. If neither is set, the element is incomplete.

JSON representation
{
  "kind": string,

  // Union field id_type can be only one of the following:
  "id": string,
  "name": string,
  // End of list of possible types for union field id_type.
}
Fields
kind

string

The kind of the entity. A kind matching regex __.*__ is reserved/read-only. A kind must not contain more than 1500 bytes when UTF-8 encoded. Cannot be "".

Union field id_type. The type of ID. id_type can be only one of the following:
id

string (int64 format)

The auto-allocated ID of the entity. Never equal to zero. Values less than zero are discouraged and may not be supported in the future.

name

string

The name of the entity. A name matching regex __.*__ is reserved/read-only. A name must not be more than 1500 bytes when UTF-8 encoded. Cannot be "".