[jpantazes]

I am running MyElipse 5.1.0 GA. The database is Sybase, and the driver is the jConnect 5.5 jdbc 2 driver. I am trying to reverse engineer the current database to java code. The problem is that when hibernate completes the reverse I get classes that represent the join tables and not just the elements that I am expecting. Here is an example.

PERSON
————
aID
name
age

CAR
———-
bID
make
model

PERSON_CARS_XREF
————————–
aID
bID
date
enabled

I am expecting to see a Person class and a Car class and that a Person has a set of Cars. Instead what I get is a Person class that has a set of PersonCarsXref types. The PersonCarsXref types has a Set of Cars. The different thing to note is the 2 extra fields (date and enabled) within the PERSON_CARS_XREF table, these are maintained by the database and can be ignored. Any help is appreciated, thanks.

[Brian Fernandes]

Hi,

I initially thought you are asking for many to many support since normally a third table is only used to relate two entities if a many to many relationship exists between them (one person has many cars & one car can be owned/used by many persons). I’m not sure “one car, many owners/users” is what you want – is it? If it is, many to many support is coming in 5.5M1 which should be released in a couple of weeks.

If you don’t really need a many to many relationship, I’m not sure I see the point of the separate PERSON_CARS_XREF table, you could put the date and enabled columns in the CAR table, and add “aID” as a foreign key which references aID in the PERSON table. Or is there some other constraint because of which you absolutely need the XREF table?

Hope this helps.

[Author]

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