Looking some sollution for my problem

avanja · **Joined:** Wed Oct 08, 2008 7:40 am **Posts:** 1

Hibernate version:
2.0.0.3001
Mapping documents:
Currency.hbm.xml

Code:

<?xml version="1.0" encoding="utf-8"?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2">
  <class name="NHibernateTest.Currency,NHibernateTest" table="Currency" lazy="false">
    <id name="IdCurrency" column="IDCurrency" type="int">
      <generator class="native" />
    </id>
    <property type="string" not-null="true" length="5" name="Symbol" column="[Symbol]" />
    <bag name="FkCurrencyName" inverse="true" lazy="true" cascade="all">
      <key column="IDCurrency" />
      <one-to-many class="NHibernateTest.CurrencyName,NHibernateTest" />
    </bag>
  </class>
</hibernate-mapping>

CurrencyName.hbm.xml

Code:

<?xml version="1.0" encoding="utf-8"?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2">
  <class name="NHibernateTest.CurrencyName,NHibernateTest" table="CurrencyName" lazy="false">
    <id name="IdCurrencyName" column="IDCurrencyName" type="int">
      <generator class="native" />
    </id>
    <property type="string" not-null="true" length="5" name="Culture" column="[Culture]" />
    <property type="string" not-null="true" length="50" name="Name" column="[Name]" />
    <many-to-one name="IdCurrency" cascade="none" column="IDCurrency" not-null="true" />
  </class>
</hibernate-mapping>

Code between sessionFactory.openSession() and session.close():
ICurrency.cs

Code:

using System;
using System.Collections;
using System.Collections.Generic;

namespace NHibernateTest
{
   public interface ICurrency
   {
      int IdCurrency { get ; set ; }
      
      string Symbol { get ; set ; }
      
      IList<ICurrencyName> FkCurrencyName { get ; set ; }

        ICurrencyName DefaultName { get; }
   }
}

ICurrencyName.cs

Code:

using System;
using System.Collections;
using System.Collections.Generic;

namespace NHibernateTest
{
   public interface ICurrencyName
   {
      int IdCurrencyName { get ; set ; }
      
      Currency IdCurrency { get ; set ; }
      
      string Culture { get ; set ; }
      
      string Name { get ; set ; }
      
         
      
   }
}

Currency.cs and CurrencyName.cs have some simple code

Full stack trace of any exception that occurs:
////
Name and version of the database you are using:
Microsoft SQL Server Express Edition 9.00.3042.00
The generated SQL (show_sql=true):
////
Debug level Hibernate log excerpt:
////

test data in tables:
Currency:

Code:

IDCurrency Symbol
1         $
2         e

CurrencyName:

Code:

IDCurrencyName   IDCurrency   Culture   Name
1            1         en-US   Dollar
2            1         fr-Fr   Doll..
3            1         mk-MK   .о.ар
4            2         en-US   Euro

Currency is the main table, Currencyname is table only has Names of the Currency in different cultures.
Currenxy has IList<ICurrencyName> FkCurrencyName that has all the names in all diferent cultures.
Most of the time FkCurrencyName will not be used. Instead we will need the CurrencyName of the default culture 'en-US' for ex.
Because of that i made new propery DefaultName in Currency.cs.

Code:

        public ICurrencyName DefaultName
        {
            get
            {
                List<ICurrencyName> t = new List<ICurrencyName>(FkCurrencyName);
                return t.Find(f => f.Culture == "en-US");
            }
        } 

But i dont like this kind of approach because if i want to get the DefaultName first i must get all the names and then filter.
I tried to map the DefaultName property in hbm file with one-on-one but i got wrong results.
My question is. Can i somehow map the DefaultName in hbm file but the result sholud depend on culture parameter.
The SQL generated code for the first Currency should somehow look like this:DefaultName = SELECT * FROM CurrencyName WHERE IDCurrency = 1 AND Culture='en-US'

gonzao_diaz · **Joined:** Mon Nov 26, 2007 2:29 pm **Posts:** 443

Apparently in your case, a one-to-one association would be the right way to go. Currency.getName()

I would make it a left join (so that currencies are returned even when no name is attached, and then I would resolve the default inside the accessor method of the class itself, (i.e., if the name is null, return a default according to the system's locale).