[web2py] Simultaneously insert in two tables within one form

[jw]

I have a quite similar question to this unrepleyd post: 
https://groups.google.com/forum/?fromgroups=#!searchin/web2py/form$20simultaneously$20insert/web2py/w44ZEk0ODsk/aCy4XmPmQmQJ

I try to realize one form within two tables get an insert by accepting the 
form.

db.card.subject_id.default = subject_id 
    db.groupCards.studyGroup_id.default = auth.user.studyGroup_id
    db.answers.user_id.default = auth.user.id
    db.answers.datetime.writable = False
    factory=SQLFORM.factory(db.card,db.groupCards,db.answers)

As you can see in both pictures and the code above, I've some 
default-values when setting up the form.
I would like to select the question (Frage), depending from the default 
subject. Now, I get all the questions in the table.
After that, the user writes his answer and the answer should be inserted in 
the answer table and in the same time with the link to the new inserted 
groupCard.
Is this possible with web2py or do I have first insert a new groupCard and 
insert a answer after this in a second form?

Sorry for my English.

Thanks in advance,
Jens

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<<attachment: database.PNG>>

<<attachment: form.PNG>>