Database Reference
In-Depth Information
+- __key__: record
| |- namespace: string
| |- app: string
| |- path: string
| |- kind: string
| |- name: string
| |- id: integer
|- __error__: string (repeated)
|- __has_error__: boolean
Comparing this with the model definitions used in the AppEngine
application, you can see that all the fields declared in the model are present
in the schema. In addition there are a couple of special fields that are added
by the import job. These fields contain additional information captured
during the transformation from Datastore entities to BigQuery records.
•
__has_error__
: Indicates if an error occurred while transforming the
row.
•
__error__
: A repeated field containing descriptions of the
transformation errors.
•
__key__
: The Datastore entity key, so that you can locate the
corresponding entity. Note that every nested entity includes this field,
but it is usually empty because nested entities are commonly purely
local to the containing entity.
The fields under
__key__
correspond to the terms documented in the
Datastore
key
reference
available
at
It is convenient to have access to the
kind
,
id,
and
name
properties, but
it is the
path
field that uniquely locates an individual entity. It is a string
representation of the array returned by the
Key.flat()
method in the
Datastore client library.
Outside of these special fields the table constructed from the snapshot
behaves just like a regular BigQuery table. Here is a simple query to look at
errors that occurred when the snapshot was loaded:
