Problems working with views

megacan · **Joined:** Fri Jan 09, 2009 1:23 pm **Posts:** 3

I was working on a very simple example to test views on NHibernate. However I couldn't get the thing to work. The code compiles, the program runs, the call to Configure() from the configuration object succedes and I can create instances of the object representing the view.
But when I try to list the content of the view the result is always an empty List. I know the view returns values because I tested it on sql server, I'm not doing any writing, deleting or updating records and the source of data from the view is from a single table.

I can't see what I'm doing wrong, maybe its something stupid but I just can't figure it out. Anyway, this is what I've got:

Database:
Table Customer(id, name)
View CustomerTypes(id, name) -> a simple SELECT * FROM CUSTOMER

The Mappings:

Code:

<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" namespace="NHibernateTest" assembly="NHibernateTest">
  <class name="Customer" table="Customer">
    <id name="Id" column="Id" type="Int64">
      <generator class="native"/>
    </id>
    <property column="Name" type="String" name="Name" length="50"/>
  </class>
</hibernate-mapping>

<?xml version="1.0" encoding="utf-8"?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2">
  <class name="NHibernateTest.CustomerTypes,NHibernateTest" table="CustomerTypes" lazy="true" mutable="false">
    <property type="long" access="field" not-null="true" name="_id" column="[id]" />
    <property type="string" access="field" not-null="true" length="50" name="_name" column="[name]" />
  </class>
</hibernate-mapping>

The Classes:

Code:

public class Customer
{
   public virtual long Id { get; set; }

   public virtual string Name { get; set; }
}

public class CustomerTypes
{
   public virtual long Id { get; set; }

   public virtual string Name { get; set; }
}

The program code:

Code:

Configuration cfg = new Configuration();
cfg.Configure();

ISessionFactory factory = cfg.BuildSessionFactory();
ISession session = factory.OpenSession();
ITransaction transaction = session.BeginTransaction();

IList l = new List<object>();

CustomerTypes ct = new CustomerTypes();
ICriteria crit = session.CreateCriteria(typeof(CustomerTypes));
crit.List(l);

transaction.Commit();
session.Close();

The list comes out empty, with 0 elements.

Can anyone see a the problem? The Customer class works fine, I can list its content, but the view doesn't work. :(

Thanks in advance.

Thomas T. · **Joined:** Fri May 25, 2007 5:06 am **Posts:** 11

Do you have "_id" and "_name" in the CustomerTypes class (there is none in your pasted code)?

wolli · **Posted:** Sat Jan 10, 2009 10:52 am

You also need a id mapping in CustomerTypes, not just the properties. Or is this left out for readability ?

megacan · **Joined:** Fri Jan 09, 2009 1:23 pm **Posts:** 3

Sorry for the late reply, I had an exam yesterday.

Ok, so there were a couple of wrong things with it:

I didn't have _id and _name mapped correctly, I don't know what happened.
I forgot to put the dam mapping as a embeded resource.
I didn't have the <id> mapping

I changed it and it works.

So, thanks for the help.

I knew It was something stupid : (