for row in result.yield_per(100):
_process_row(row)
-The ``stream_results`` option is also available with the ORM. When using the
-ORM, either the :meth:`_engine.Result.yield_per` or :meth:`_engine.Result.partitions`
-methods should be used to set the number of ORM rows to be buffered each time
-while yielding::
+The ``stream_results`` option is also available with the ORM. When using the
+ORM, the :meth:`_engine.Result.yield_per` method should be used to set the
+number of ORM rows to be buffered each time while yielding
+(:meth:`_engine.Result.partitions` uses the "yield per" value by default for
+partition size)::
with orm.Session(engine) as session:
result = session.execute(
select(User).order_by(User_id).execution_options(stream_results=True),
)
- for partition in result.partitions(100):
+ for partition in result.yield_per(100).partitions():
_process_rows(partition)
.. note:: ORM result sets currently must make use of :meth:`_engine.Result.yield_per`
- or :meth:`_engine.Result.partitions` in order to achieve streaming ORM results.
- If either of these methods are not used to set the number of rows to
+ in order to achieve streaming ORM results.
+ If the method is not used to set the number of rows to
fetch before yielding, the entire result is fetched before rows are yielded.
This may change in a future release so that the automatic buffer size used
by :class:`_engine.Connection` takes place for ORM results as well.
# process row
+.. seealso::
+
+ :ref:`orm_queryguide_yield_per` - in the :ref:`queryguide_toplevel`
+
+ :meth:`_engine.Result.partitions`
+
+
.. _schema_translating:
...
For expediency, the :meth:`_engine.Result.yield_per` method may also be used
-with an ORM-enabled result set, which will have the same effect at result
-fetching time as if the ``yield_per`` execution option were used. The
-:meth:`_engine.Result.partitions` method, if used, automatically uses the
-number sent to :meth:`_engine.Result.yield_per` as the number of rows in each
-partition::
+with an ORM-enabled result set, which will have the similar effect at result
+fetching time as if the ``yield_per`` execution option were used, with the
+exception that ``stream_results`` option, described below, is not set
+automatically. The :meth:`_engine.Result.partitions` method, if used,
+automatically uses the number sent to :meth:`_engine.Result.yield_per` as the
+number of rows in each partition::
>>> stmt = select(User)
- {sql}>>> for partition in session.execute(stmt).yield_per(10).partitions():
+ {sql} >>> for partition in session.execute(
+ ... stmt, execution_options={"stream_results": True}
+ ... ).yield_per(10).partitions():
... for row in partition:
... print(row)
SELECT user_account.id, user_account.name, user_account.fullname