Collections
Classes for representing collections for the Google Cloud Firestore API.
class google.cloud.firestore_v1.collection.CollectionReference(*path, **kwargs)
Bases: object
A reference to a collection in a Firestore database.
The collection may already exist or this class can facilitate creation of documents within the collection.
Parameters
path (Tuple[str, **...]) – The components in the collection path. This is a series of strings representing each collection and sub-collection ID, as well as the document IDs for any documents that contain a sub-collection.
kwargs (dict) – The keyword arguments for the constructor. The only supported keyword is
client
and it must be aClient
if provided. It represents the client that created this collection reference.
Raises
ValueError – if
* the
path
is empty * there are an even number of elements * a collection ID inpath
is not a string * a document ID inpath
is not a stringTypeError – If a keyword other than
client
is used.
add(document_data, document_id=None)
Create a document in the Firestore database with the provided data.
Parameters
document_data (dict) – Property names and values to use for creating the document.
document_id (Optional[str]) – The document identifier within the current collection. If not provided, an ID will be automatically assigned by the server (the assigned ID will be a random 20 character string composed of digits, uppercase and lowercase letters).
Returns
Pair of
The
update_time
when the document was created/overwritten.A document reference for the created document.
Return type
Tuple[
google.protobuf.timestamp_pb2.Timestamp
,DocumentReference
]Raises
Conflict – If
document_id
is provided and the document already exists.
document(document_id=None)
Create a sub-document underneath the current collection.
Parameters
document_id (Optional[str]) – The document identifier within the current collection. If not provided, will default to a random 20 character string composed of digits, uppercase and lowercase and letters.
Returns
The child document.
Return type
end_at(document_fields)
End query at a cursor with this collection as parent.
See
end_at()
for
more information on this method.
Parameters
document_fields (Union[
DocumentSnapshot
, dict, list, tuple]) – A document snapshot or a dictionary/list/tuple of fields representing a query results cursor. A cursor is a collection of values that represent a position in a query result set.Returns
A query with cursor.
Return type
end_before(document_fields)
End query before a cursor with this collection as parent.
See
end_before()
for
more information on this method.
Parameters
document_fields (Union[
DocumentSnapshot
, dict, list, tuple]) – A document snapshot or a dictionary/list/tuple of fields representing a query results cursor. A cursor is a collection of values that represent a position in a query result set.Returns
A query with cursor.
Return type
get(transaction=None)
Deprecated alias for stream()
.
property id()
The collection identifier.
Returns
The last component of the path.
Return type
limit(count)
Create a limited query with this collection as parent.
See
limit()
for
more information on this method.
Parameters
count (int) – Maximum number of documents to return that match the query.
Returns
A limited query.
Return type
list_documents(page_size=None)
List all subdocuments of the current collection.
Parameters
page_size (Optional[int]]) – The maximum number of documents
each page of results from this request. Non-positive values (in) –
ignored. Defaults to a sensible value set by the API. (are) –
Returns
iterator of subdocuments of the current collection. If the collection does not exist at the time of snapshot, the iterator will be empty
Return type
Sequence[
DocumentReference
]
offset(num_to_skip)
Skip to an offset in a query with this collection as parent.
See
offset()
for
more information on this method.
Parameters
num_to_skip (int) – The number of results to skip at the beginning of query results. (Must be non-negative.)
Returns
An offset query.
Return type
on_snapshot(callback)
Monitor the documents in this collection.
This starts a watch on this collection using a background thread. The provided callback is run on the snapshot of the documents.
Parameters
callback (Callable[[
CollectionSnapshot
], NoneType]) – a callback to run when a change occurs.
Example
from google.cloud import firestore_v1
db = firestore_v1.Client() collection_ref = db.collection(u’users’)
def on_snapshot(collection_snapshot):
for doc in collection_snapshot.documents:
print(u’{} => {}’.format(doc.id, doc.to_dict()))
Watch this collection
collection_watch = collection_ref.on_snapshot(on_snapshot)
Terminate this watch
collection_watch.unsubscribe()
order_by(field_path, **kwargs)
Create an “order by” query with this collection as parent.
See
order_by()
for
more information on this method.
Parameters
field_path (str) – A field path (
.
-delimited list of field names) on which to order the query results.kwargs (Dict[str, *[Any](types.md#google.cloud.firestore_v1.types.Any)]*) – The keyword arguments to pass along to the query. The only supported keyword is
direction
, seeorder_by()
for more information.
Returns
An “order by” query.
Return type
property parent()
Document that owns the current collection.
Returns
The parent document, if the current collection is not a top-level collection.
Return type
Optional[
DocumentReference
]
select(field_paths)
Create a “select” query with this collection as parent.
See
select()
for
more information on this method.
Parameters
field_paths (Iterable[str, **...]) – An iterable of field paths (
.
-delimited list of field names) to use as a projection of document fields in the query results.Returns
A “projected” query.
Return type
start_after(document_fields)
Start query after a cursor with this collection as parent.
See
start_after()
for
more information on this method.
Parameters
document_fields (Union[
DocumentSnapshot
, dict, list, tuple]) – A document snapshot or a dictionary/list/tuple of fields representing a query results cursor. A cursor is a collection of values that represent a position in a query result set.Returns
A query with cursor.
Return type
start_at(document_fields)
Start query at a cursor with this collection as parent.
See
start_at()
for
more information on this method.
Parameters
document_fields (Union[
DocumentSnapshot
, dict, list, tuple]) – A document snapshot or a dictionary/list/tuple of fields representing a query results cursor. A cursor is a collection of values that represent a position in a query result set.Returns
A query with cursor.
Return type
stream(transaction=None)
Read the documents in this collection.
This sends a RunQuery
RPC and then returns an iterator which
consumes each document returned in the stream of RunQueryResponse
messages.
NOTE: The underlying stream of responses will time out after
the max_rpc_timeout_millis
value set in the GAPIC
client configuration for the RunQuery
API. Snapshots
not consumed from the iterator before that point will be lost.
If a transaction
is used and it already has write operations
added, this method cannot be used (i.e. read-after-write is not
allowed).
Parameters
transaction (Optional[
Transaction
]) – An existing transaction that the query will run in.Yields
DocumentSnapshot
– The next document that fulfills the query.
where(field_path, op_string, value)
Create a “where” query with this collection as parent.
See
where()
for
more information on this method.
Parameters
field_path (str) – A field path (
.
-delimited list of field names) for the field to filter on.op_string (str) – A comparison operation in the form of a string. Acceptable values are
<
,<=
,==
,>=
and>
.value (Any) – The value to compare the field against in the filter. If
value
isNone
or a NaN, then==
is the only allowed operation.
Returns
A filtered query.
Return type