Fluent NHibernate: How to tell it not to map a base class

问题

I have been googling and stackoverflowing for the last two hours and couldn't find an answer for my question:

I'm using ASP.NET MVC and NHibernate and all I'm trying to do is to manually map my entities without mapping its base class. I'm using the following convention:

public class Car : EntityBase
{
    public virtual User User { get; set; }
    public virtual string PlateNumber { get; set; }
    public virtual string Make { get; set; }
    public virtual string Model { get; set; }
    public virtual int Year { get; set; }
    public virtual string Color { get; set; }
    public virtual string Insurer { get; set; }
    public virtual string PolicyHolder { get; set; }
}

Where EntityBase SHOULD NOT be mapped.

My NHibernate helper class looks like this:

namespace Models.Repository
{
    public class NHibernateHelper
    {
        private static string connectionString;
        private static ISessionFactory sessionFactory;
        private static FluentConfiguration config;

        /// <summary>
        /// Gets a Session for NHibernate.
        /// </summary>
        /// <value>The session factory.</value>
        private static ISessionFactory SessionFactory
        {
            get
            {
                if (sessionFactory == null)
                {
                    // Get the connection string
                    connectionString = ConfigurationManager.ConnectionStrings["connectionString"].ConnectionString;
                    // Build the configuration
                    config = Fluently.Configure().Database(PostgreSQLConfiguration.PostgreSQL82.ConnectionString(connectionString));
                    // Add the mappings
                    config.Mappings(AddMappings);
                    // Build the session factory
                    sessionFactory = config.BuildSessionFactory();
                }
                return sessionFactory;
            }
        }

        /// <summary>
        /// Add the mappings.
        /// </summary>
        /// <param name="mapConfig">The map config.</param>
        private static void AddMappings(MappingConfiguration mapConfig)
        {
            // Load the assembly where the entities live
            Assembly assembly = Assembly.Load("myProject");
            mapConfig.FluentMappings.AddFromAssembly(assembly);
            // Ignore base types
            var autoMap = AutoMap.Assembly(assembly).IgnoreBase<EntityBase>().IgnoreBase<EntityBaseValidation>();
            mapConfig.AutoMappings.Add(autoMap);
            // Merge the mappings
            mapConfig.MergeMappings();
        }

        /// <summary>
        /// Opens a session creating a DB connection using the SessionFactory.
        /// </summary>
        /// <returns></returns>
        public static ISession OpenSession()
        {
            return SessionFactory.OpenSession();
        }

        /// <summary>
        /// Closes the NHibernate session.
        /// </summary>
        public static void CloseSession()
        {
            SessionFactory.Close();
        }
    }
}

The error that I'm getting now, is:

System.ArgumentException: The type or method has 2 generic parameter(s), but 1 generic argument(s) were provided. A generic argument must be provided for each generic parameter

This happens when I try to add the mappings. Is there any other way to manually map your entities and tell NHibernate not to map a base class?

回答1:

If you don't want to automap a class, I would recommend using IAutoMappingOverride<T>. I don't about your database, but it might look like:

public class CarOverride : IAutoMappingOverride<Car>
{

    public void Override(AutoMapping<Car> mapping){
        mapping.Id( x => x.Id, "CarId")
          .UnsavedValue(0)
          .GeneratedBy.Identity();


        mapping.References(x => x.User, "UserId").Not.Nullable();

        mapping.Map(x => x.PlateNumber, "PlateNumber");
        // other properties
    }
}

Assuming you keep these maps centrally located, you could then load them on your autoMap:

var autoMap = AutoMap.Assembly(assembly).IgnoreBase<EntityBase>().IgnoreBase<EntityBaseValidation>()
                .UseOverridesFromAssemblyOf<CarOverride>();

回答2:

IncludeBase<T>

AutoMap.AssemblyOf<Entity>()
  .IgnoreBase<Entity>()
  .Where(t => t.Namespace == "Entities");

Read more here http://wiki.fluentnhibernate.org/Auto_mapping :)

回答3:

I know it's an old question but I think that some things are missing here :

When you use IgnoreBase<T> you are telling that you don't want to map inheritance into your database but Fluent Nhibernate will still map your base class as an individual class while you don't tell it not to do that, so if you want to tell Fluent Nhibnernate not to map the class itself you should inherit DefaultAutoMapConfiguration class and override its bool ShouldMap(Type type) and return false if the type is any type that you don't want to map it at all.

When you use AutoMapping generally you don't need any other mapping classes or overrides unless you want to make a change in your mappings and it's not possible doing that using Conventions or you just want to override a small part of one class.(Although you can do the same using Conventions and Inspectors)

回答4:

You can use IsBaseType convention for your automappings

来源：https://stackoverflow.com/questions/1858245/fluent-nhibernate-how-to-tell-it-not-to-map-a-base-class

标签

asp.net-mvc

nhibernate

fluent-nhibernate