I'm trying get NHibernate to work with tables that are not normalized properly (and I can't do anything about it). I posted this as part of another question last week, but nobody addressed this part.

Here is a sample table:

CONTACT1
COMPANY, ... PHONE1, PHONE2, PHONE3

I'm having trouble dealing with the multiple PHONE fields. I want them each in there own class of:

PhoneNumber
Number


Here is a sniplet of my current mapping file. It currently only supports accessing the PHONE1 field and ignores the rest:





If it makes a difference, this class only needs to reads the data, it does not write it back.

I'm very new to Hibernate and I'm trying to wrap my head around all of this. I've read the documentation on hibernate.org but I couldn't find any example like this... if anyone can point me in the right direction I'd be very appreciative.

Thanks,
Patrick

I think you have two options:

1. create some views in the database to normalise your data. I have used this approach in the past and works nicely if you need only read access to your data.

2. other approach would be to declare your phone1,phone2, phone3 as private members of your object and define in your object as a public property the collection of PhoneNumbers. you can initialize the collection in the constructor or lazily in your getter. In this way you can keep the mess private.

HTH,
radu

Thanks for the reply, unfortunately neither solution would work in my case. I realize creating a view could help solve the problem, but I'm trying to avoid that.

I also can't have the phone numbers just stored as strings in a collection, they need to be each in their own class (and then a collection a PhoneNumber objects contained in the Contact object)

I'm starting to get the feeling that Hibernate does not support what I'm trying to do.

Thanks,
Patrick

Try mapping your scenario as a Collection of Components. Please see following url's for documentation:

http://www.hibernate.org/hib_docs/reference/en/html/components.html

http://ndpsoftware.com/HibernateMappingCheatSheet.html

Try mapping your scenario as a Collection of Components. Please see following url's for documentation:

http://www.hibernate.org/hib_docs/reference/en/html/components.html

http://ndpsoftware.com/HibernateMappingCheatSheet.html

Samujab,

But how do components help me instantiating 3 separate phone number classes? I've read the docs, I just re-read that section now, I don't see how this can help. Can you show me?

I need to map 3 PhoneNumber objects (as a separate classs, not an array of strings or other structures) to one Record.

Thanks, sorry if I'm dense,
Patrick

I did not fully understand your problem before suggesting to try a collection of Components.

Have you tried if creating a Custom User type could help solve this problem. Let me see if I can come up with an example.

dpseal, you need to understand that bag (and other collections as well) can't help you in this case. Collections are for mapping data that resides in another table, binded by means of foreign key.
As radu suggested you need to:
1. Map your fields with phone numbers into three separate members of your "Contact" class. Those members could be private and they could be either strings, or instances of your "PhoneNumber" class. In latter case, you will need to create custom type, or use component mapping.
2. If you don't want to access phone numbers as Phone1, Phone2 and Phone3, but rather want to have a collection (list, for example) of numbers, then after you "Contact" class will be instantiated and filled with data, you can take three separated members with phone numbers and manually create a collection with numbers.

Here is how you can solve this by using CompositeUserType

Create a new Custom User Type by implementing the ICompositeUserType interface and implement all the relevant methods. Specify your mapping as

In the NullSafeGet method return an ArrayList of your PhoneNumber class:


Your Contact class would look like this:



Hope this helps.......

Very good solution, samujob!

yes, i learned something new as well.. thank you!

Thanks Samujob, that looks great! I'm going to try it out later today.