Hi Diana,
thank you for your help, but unfortunately my problem still exists.
In my case the lazy attribute for the myChildren relationship has
absolutely no effect!
At this point one more information is important: I build and populate the
database with one session, and then open a new session and call
showDatabase.
If you populate the database with one session, and then call showDatabase
with the same (now not empty) session,
then the instances are already in the session and sqlalchemy don't fire new
queries for access to the myChildren attribute of human.
So, it is important to call showDatabase with an empty session to reproduce
my issue.
One more information could be important:
If I load a woman instance and access myChildren with:
woman = session.query(Woman).one()
print woman.myChildren
then sqlalchemy emits an extra sql query on the access to myChildren and
ignore my lazy='subquery' or lazy='joined' parameter for the mychildren
relationship configuration.
But if I modify the query like this:
woman = session.query(Woman).options(subqueryload('myChildren')).one()
print woman.myChildren
then sqlalchemy load the woman and all children at once! Exactly what I
need.
But this makes completely no sense to me, i thought that subqueryload()
just overload the load strategie for a relationship.
So myChildren = relationship('Child', secondary=link_table,
lazy='subquery') and subqueryload('myChildren') should be equivalent.
Why is there a difference?
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