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Hello all,
I'm coming across a little problem. In my database
design I have the following tables:
PROPOSAL is linked to PROPOSAL_ROLE by
1-M
PROPOSAL_ROLE is linked to USER by
M-1.
Therefore PROPOSAL_ROLE is used as a join table
that will link the two other tables. This is used because a user can play a
certain role on many different proposals, and a proposal can have many users
that it's involved with.
I've currently implemented the PROPOSAL_ROLE table
as ProposalRole CMP Entity bean and specified the above relationships in
ejb-jar.xml, but I'm looking at another example using WebLogic 6.1, and in the
file weblogic-cmp-rdbms-jar.xml, they are specifiying the join table
relationships and NOT creating a CMP entity bean for the join table, but instead
just specifying the MANY-TO-MANY relationships between the two beans in
ejb-jar.xml. Therefore in my example the proposal bean would
proposal.getUsers(), and the user bean would have user.getProposals(). This way
I would not have to model the ProposalRole as an entity bean with getProposal()
and getUser() methods, rather this would happen "behind the scenes." However, in
my join table PROPOSAL_ROLE, I am storing two other fields that are important in
recognizing the particular relationship. I've included a "role" and "effort
percent" column that give particular data about the relationship that a user has
with a particular proposal in the system. So I can see why I would want to have
a ProposalRoleBean in this case to be able to access that data.
I guess what I'm really asking is this: Do all JOIN
tables have to modeled as CMP Entity beans if the table in itself contains
columns of data on top of just storing the two foreign keys of the other two
linked tables? Also, how does one specify the links between the join table and
the two other tables in Resin (similar to how weblogic-cmp-rdbms-jar.xml does
it)?
Thanks for any suggestions!
Ryan LeCompte
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- Re: Do join tables have to be represented as a CMP Entity? Ryan LeCompte
- Re: Do join tables have to be represented as a CMP Enti... Robert Kr�ger
- Re: Do join tables have to be represented as a CMP Enti... Ramakrishna N
