On 5/3/06, Fredrik Liden <[EMAIL PROTECTED]> wrote:
I'm trying to figure out two queries from the following structure.
SURVEY
SurveyID (PK)
PERSON_SURVEY
PersonID (PK,FK)
SurveyID (PK,FK)
PERSON
PersonID (PK)
1. I have a join table PERSON_SURVEY with a composite key of PersonID
and SurveyID. How can I query for all the entries where PersonID =
'something'. Do I use an expression or a path? Since this is a composite
key and is part of the PK. In general, is it preferred to stay away from
composite keys in the join tables?
Yes, I recommend using a composite join table. Cayenne has excellent
support for this situation. Make sure to mark the reverse
DbRelationships as "to dep key". You'll probably need to manually
add ObjRelationships to your Person and Survey ObjEntities.
Once you've configured everything correctly, your join tables will be
invisible to your application. You'll be able to use
person.addToSurveyList() and person.getSurveyList() and
survey.addToPersonList() and survey.getPersonList() transparently.
