I know how to get the columns that would be returned from a select statement but how do I get the entities that would be returned from an sqlalchemy.orm.Query object?
>>> sess = Session()
>>> q = sess.query(Entity1, Entity2)
>>> q.statement.c.keys()
['e1_col1', 'e1_col2', ..., 'e2_col1', 'e2_col2, ...]
I want [Entity1, Entity2] or something similar!
Update: A better approach now exists, see @exhuma answer. My old answer from 2010 follows.
You can try this:
[e.mapper.class_ for e in q._entities]
Although I would prefer not to use _entities attribute directly and find some other way to access it, but AFAIK there is none.
_entities no longer exists on the query object. This answer is obsolete. See stackoverflow.com/a/72978285/160665This is indirectly available via Query.column_descriptions:
entities = {item['entity'] for item in query.column_descriptions}
This uses a set instead of a list to avoid duplicates in case of a query that selects specific columns (f.ex.: query = session.query(Foo.bar, Foo.baz)). The column_descriptions attribute contains an entry for each selected column so this would cause duplicates.
sqlalchemy_utils module has a function called get_query_entities that does the job
get_query_entities does not seem to exist on that library. And there is a "native" way to solve this. See stackoverflow.com/a/72978285/160665