A Datastore key ( detailed presentation ) uniquely identifies an entity within the Datastore.
A key is represented in JSON by an object with the following structure:
{
"partitionId": {
"datasetId": string,
"namespace": string
},
"path": [
{
"kind": string,
"id": long,
"name": string
}
]
},
| Property name | Value | Description | Notes |
|---|---|---|---|
partitionId
|
nested object
|
Entities are partitioned into subsets, currently identified by a dataset (usually implicitly specified by the project) and namespace ID. Queries are scoped to a single partition. | |
partitionId.
datasetId
|
string
|
The dataset ID. | |
partitionId.
namespace
|
string
|
The namespace. | |
path[]
|
list
|
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 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. A path can never be empty. | |
path[].
kind
|
string
|
The kind of the entity. A kind matching regex "__.*__" is reserved/read-only. A kind must not contain more than 500 characters. Cannot be "". | |
path[].
id
|
long
|
The ID of the entity. Never equal to zero. Values less than zero are discouraged and will not be supported in the future. | |
path[].
name
|
string
|
The name of the entity. A name matching regex "__.*__" is reserved/read-only. A name must not be more than 500 characters. Cannot be "". |