def _try_fetch(self, size=None):
"""Try to start fetching data, if not yet started.
Mutates self to indicate that iteration has started.
"""
if self._query_job is None:
raise exceptions.InterfaceError(
"No query results: execute() must be called before fetch.")
if self._query_job.dry_run:
self._query_data = iter([])
return
is_dml = (self._query_job.statement_type
and self._query_job.statement_type.upper() != "SELECT")
if is_dml:
self._query_data = iter([])
return
if self._query_data is None:
client = self.connection._client
bqstorage_client = self.connection._bqstorage_client
if bqstorage_client is not None:
rows_iterable = self._bqstorage_fetch(bqstorage_client)
self._query_data = _helpers.to_bq_table_rows(rows_iterable)
return
rows_iter = client.list_rows(
self._query_job.destination,
selected_fields=self._query_job._query_results.schema,
page_size=self.arraysize,
)
self._query_data = iter(rows_iter)
def fetchmany(self, size=None):
"""Fetch multiple results from the last ``execute*()`` call.
.. note::
The size parameter is not used for the request/response size.
Set the ``arraysize`` attribute before calling ``execute()`` to
set the batch size.
:type size: int
:param size:
(Optional) Maximum number of rows to return. Defaults to the
``arraysize`` property value.
:rtype: List[tuple]
:returns: A list of rows.
:raises: :class:`~google.cloud.bigquery.dbapi.InterfaceError`
if called before ``execute()``.
"""
if self._query_data is None:
raise exceptions.InterfaceError(
'No query results: execute() must be called before fetch.')
if size is None:
size = self.arraysize
rows = []
for row in self._query_data:
rows.append(row)
if len(rows) >= size:
break
return rows
def fetchall(self):
"""Fetch all remaining results from the last ``execute*()`` call.
:rtype: List[tuple]
:returns: A list of all the rows in the results.
:raises: :class:`~google.cloud.bigquery.dbapi.InterfaceError`
if called before ``execute()``.
"""
if self._query_data is None:
raise exceptions.InterfaceError(
'No query results: execute() must be called before fetch.')
return [row for row in self._query_data]
def _try_fetch(self, size=None):
"""Try to start fetching data, if not yet started.
Mutates self to indicate that iteration has started.
"""
if self._query_results is None:
raise exceptions.InterfaceError(
'No query results: execute() must be called before fetch.')
if size is None:
size = self.arraysize
if self._query_data is None:
self._query_data = iter(
self._query_results.fetch_data(max_results=size))
def _try_fetch(self, size=None):
"""Try to start fetching data, if not yet started.
Mutates self to indicate that iteration has started.
"""
if self._query_job is None:
raise exceptions.InterfaceError(
"No query results: execute() must be called before fetch.")
is_dml = (self._query_job.statement_type
and self._query_job.statement_type.upper() != "SELECT")
if is_dml:
self._query_data = iter([])
return
if self._query_data is None:
client = self.connection._client
bqstorage_client = self.connection._bqstorage_client
if bqstorage_client is not None:
try:
rows_iterable = self._bqstorage_fetch(bqstorage_client)
self._query_data = _helpers.to_bq_table_rows(rows_iterable)
return
except google.api_core.exceptions.GoogleAPICallError as exc:
# NOTE: Forbidden is a subclass of GoogleAPICallError
if isinstance(exc, google.api_core.exceptions.Forbidden):
# Don't hide errors such as insufficient permissions to create
# a read session, or the API is not enabled. Both of those are
# clearly problems if the developer has explicitly asked for
# BigQuery Storage API support.
raise
# There is an issue with reading from small anonymous
# query results tables. If such an error occurs, we silence
# it in order to try again with the tabledata.list API.
_LOGGER.debug(
"Error fetching data with BigQuery Storage API, "
"falling back to tabledata.list API.")
rows_iter = client.list_rows(
self._query_job.destination,
selected_fields=self._query_job._query_results.schema,
page_size=self.arraysize,
)
self._query_data = iter(rows_iter)
def fetchone(self):
"""Fetch a single row from the results of the last ``execute*()`` call.
:rtype: tuple
:returns:
A tuple representing a row or ``None`` if no more data is
available.
:raises: :class:`~google.cloud.bigquery.dbapi.InterfaceError`
if called before ``execute()``.
"""
if self._query_data is None:
raise exceptions.InterfaceError(
'No query results: execute() must be called before fetch.')
try:
return six.next(self._query_data)
except StopIteration:
return None
def _try_fetch(self, size=None):
"""Try to start fetching data, if not yet started.
Mutates self to indicate that iteration has started.
"""
if self._query_job is None:
raise exceptions.InterfaceError(
'No query results: execute() must be called before fetch.')
is_dml = (self._query_job.statement_type
and self._query_job.statement_type.upper() != 'SELECT')
if is_dml:
self._query_data = iter([])
return
if self._query_data is None:
client = self.connection._client
rows_iter = client.list_rows(
self._query_job.destination,
selected_fields=self._query_job._query_results.schema,
page_size=self.arraysize)
self._query_data = iter(rows_iter)
def _try_fetch(self, size=None):
"""Try to start fetching data, if not yet started.
Mutates self to indicate that iteration has started.
"""
if self._query_job is None:
raise exceptions.InterfaceError(
"No query results: execute() must be called before fetch.")
if self._query_job.dry_run:
self._query_data = iter([])
return
if self._query_data is None:
bqstorage_client = self.connection._bqstorage_client
if bqstorage_client is not None:
rows_iterable = self._bqstorage_fetch(bqstorage_client)
self._query_data = _helpers.to_bq_table_rows(rows_iterable)
return
rows_iter = self._query_job.result(page_size=self.arraysize)
self._query_data = iter(rows_iter)
