Question

I’m creating my first application using NHibernate. Unfortunately, I encountered a problem I cannot solve:

I’m accessing the database from “DAL” project that contains CRUD methods and NHibernateHelper class.

I wrote a test project and I tried to add an object to DB – it works perfectly. But when I try to call the same method from my application’s ViewModel (it’s in the other project as well) it throws an error at configuration.BuildSessionFactory() in the code below:

private static ISessionFactory SessionFactory
    {
        get
        {
            if (_sessionFactory == null)
            {
                var configuration = new Configuration();
                configuration.Configure();
                configuration.AddAssembly(typeof(Address).Assembly);
                _sessionFactory = configuration.BuildSessionFactory();
            }
            return _sessionFactory;
        }
    }

The exception:

NHibernate.HibernateException: Could not create the driver from NHibernate.Driver.OracleDataClientDriver.
System.Reflection.TargetInvocationException: {"Exception has been thrown by the target of an invocation."}
System.NullReferenceException: {"Object reference not set to an instance of an object."}

In my test project I added reference to Oracle.DataAccess.dll and created App.config as it throws the same error without it:

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<runtime>
<assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
  <qualifyAssembly partialName="Oracle.DataAccess"
         fullName="Oracle.DataAccess,
                        Version=4.112.2.0,
                       Culture=neutral,
                       PublicKeyToken=89b483f429c47342" />
</assemblyBinding>
</runtime>
</configuration>

I made the same thing in my project containing ViewModel in which I need to get data from DB, but it didn’t help. I also set Copy Local to True for that reference, but to no avail.

It’s my App.config:

<?xml version="1.0" encoding="utf-8" ?>
<hibernate-configuration xmlns="urn:nhibernate-configuration-2.2">
  <session-factory>
    <property name="connection.provider">
      NHibernate.Connection.DriverConnectionProvider
    </property>
    <property name="dialect">
      NHibernate.Dialect.Oracle10gDialect
    </property>
    <property name="connection.driver_class">
      NHibernate.Driver.OracleDataClientDriver
    </property>
    <property name="connection.connection_string">
      User Id=****;
      Password=****;
      Data Source=(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=
      (PROTOCOL=TCP)(HOST=localhost)(PORT=1521)))
      (CONNECT_DATA=(SERVICE_NAME=xe)));
      Pooling=true;
      Enlist=false;
      Statement Cache Size=50;
      Min Pool Size=10;
      Incr Pool Size=5;
      Decr Pool Size=2;
    </property>
    <property name="show_sql">
      true
    </property>
  </session-factory>
</hibernate-configuration>

I’m using NHibernate v 3.3.1.4000, Oracle 11g xe and 64-bit Windows 7 (I cannot choose to debug on 32 or 64-bit, there is only one possibility to select: “Active (Any CPU)” )

What can be the reason that I can use it from test project, but I cannot do it from the other?

Thank you in advance

Answer 1

The problem is solved. I had to put app.config in main project, not in dll library from which I use the database. I didn’t know that app.config placed in class library will be ignored.