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| -rw-r--r-- | doc/source/usage.rst | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/doc/source/usage.rst b/doc/source/usage.rst index 448afaa..1b2d996 100644 --- a/doc/source/usage.rst +++ b/doc/source/usage.rst @@ -75,6 +75,21 @@ decorator. Each function must receive the context argument: results = some_reader_api_function(context) some_writer_api_function(context, 5, 10) + +``connection`` modifier can be used when a :class:`.Session` object is not +needed, e.g. when `SQLAlchemy Core <http://docs.sqlalchemy.org/en/latest/core/>`_ +is preferred: + +.. code:: python + + @enginefacade.reader.connection + def _refresh_from_db(context, cache): + sel = sa.select([table.c.id, table.c.name]) + res = context.connection.execute(sel).fetchall() + cache.id_cache = {r[1]: r[0] for r in res} + cache.str_cache = {r[0]: r[1] for r in res} + + .. note:: The ``context.session`` and ``context.connection`` attributes must be accessed within the scope of an appropriate writer/reader block (either the decorator or contextmanager approach). An AttributeError is |