Hello Hibernate users!

I've got the following problem:

In my domain model I have person and address types. Each person always has a main address assigned, and also 0..2 other addresses. The total number of addresses can never exceed 3.

Relations are bi-directional, so all addresses know about the person they belong to.

I could map this as entity relations with a set containing all addresses and an additional one-to-one association for the main address, but I think it would be much faster to map this as components.

Of course the main address would be mapped as a simple address component, but how do I map the other 0..2 addresses so I don't have to care about the order or if they exist at all? Preferably this would be mapped as a set, wouldn't it?

Some help would be appreciated... :-)

Greetings
Gregor


Hibernate version: 2.1

Name and version of the database: MySQL 4.1 NDB Cluster

Sounds like you have some complex behavior there. It's almost like you want an Addresses object that has a Primary address, and then a Set of no more than 2 alternative addresses.

You could settle for just modelling it as 3 Address components, but that would require all kinds of logic everywhere to check to see if the alternative addresses are blank.

Personally, I'd probably go for a custom UserType in this case. It's not that hard to do really wild and wooly mappings. I'd go for an object like:

public class Address {
... all your address, city, state accessor/mutator stuff here...
}

public class Addresses {
private Address primary;
private Set alternatives;
public Address getPrimary() { return primary; }
public setPrimary(Address p) { this.primary = p; }
public Set getAlternatives() { return alternatives; }
public void setAlternatives(Set s) { this.alternatives = s; }
}

Then, just create a CompositeUserType that reads all 15 or so fields from the data set and constructs your custom type. The only gotcha I've ever had is in storing this in the second level cache. Good luck! Post if you have trouble.

ok,thank your very much for your help, I'll see how it works :-)

Come to think of it, since you're using a UserType, you could map the alternate addresses as an array rather than a Set so that you can have stronger typing.

Something more like



I think that'd be better, but personal choice!