Many-to-Many mapping example

gcook1@shaw.ca · **Joined:** Tue Feb 07, 2006 4:27 pm **Posts:** 69

Hi all,

I'm obviously new to NHibernate and am having trouble getting a
many-to-many mapping working properly.

Does someone have a working sample, including table DDL for SQL Server that I can use as a reference?

I've had no luck finding any examples with a many-to-many
relationship mapped.

Thanks in advance.

Greg

jt_1000 · **Posted:** Tue Mar 28, 2006 12:36 pm

check out one of my recent posts on many-to-many:

http://forum.hibernate.org/viewtopic.php?t=955973&highlight=mtom+manytomany+mm

jt_1000 · **Posted:** Tue Mar 28, 2006 12:37 pm

if that doesn't work for you, then reply, and I'll muster up a working example for you. complete with SQL.

gcook1@shaw.ca · **Joined:** Tue Feb 07, 2006 4:27 pm **Posts:** 69

Thanks very much. I'll take a look for sure.

This appears to set up a bi-directional relationship.

It is possible to setup a uni-directional relationship

Table A navigates to Table C via the xref table B, but I don't need to
be able to go from C back to A..

Hope this makes sense.

Thanks again.

jt_1000 · **Posted:** Tue Mar 28, 2006 2:15 pm

don't put the Set/List on one side, and don't provide it's mapping in that class.

gcook1@shaw.ca · **Joined:** Tue Feb 07, 2006 4:27 pm **Posts:** 69

Hi JT,

Using the Link you provided, I have my example working. It works on both a read and a new insert.

Thanks very much for your assistance. This is soooo much better than
writing the SQL yourself.

I've used TOPLink for Java in the Java space and am very happy that
there is a decent ORM tool for .net now and a community of developers
to collaborate with.

Thanks again.

jt_1000 · **Posted:** Tue Mar 28, 2006 5:18 pm

that is good to hear - I am glad to help.