ansaurus

Question

Fluent NHibernate (with automapping) not saving join table values in many-to-many

Answer 1

+2 A:

I might be mistaken, but it looks like you marked the relationship as "inverse" for both sides.

You should do this for only one side of the relationship, and make sure you call Save on the other one.

Also, I believe the relationship needs to be valid on both sides before you save (add cat to prod.Categories, in addition to what you're already doing).

My understanding of these kinds of relationships is admittedly fuzzy, but this is what my research over the months has come up with (and solved some of my own problems).

Sapph 2010-01-08 16:20:11

ive got Categories = new List<Category>(new[] { cat }) in my product initializer, which is shorthand for "Make a new list<category>, and add a new array of Categories to it with a single element (cat)". I tried removing both inverses, and adding it to one or the other side and nothing worked. :( Thanks for the answer though, pretty sure I want to inverse the category, so I just call save on product. (once I get this issue sorted out)

Matt Briggs 2010-01-08 16:44:45

Oops, I'm very sorry, should have read your code more carefully (missed the initializer). Tangentially, though, you could also just do `new List<Category>() { cat }` and skip the array part.

Sapph 2010-01-08 16:49:46

Answer 2

A:

You have inverse on the wrong side of the association. Inverse means "the other side manages this association".

What you need is either to remove Inverse on Category and put it on Product, or change Product to be the 'owning' entity, like this:

//make sure to add it to BOTH sides of the association
product.Categories.Add(cat);
cat.Products.Add(product);

db.Save(cat);  //if Product has Inverse
/* or */
db.Save(prod); //if Category has Inverse

Ben Scheirman 2010-01-12 15:23:33

tried flipping the inverse, still no go :(

Matt Briggs 2010-01-12 16:49:39

Answer 3

A:

What about if you were to apply the fluent mappings for Product and Category first, before the automapping. For example,

public class Product
{
    public virtual int Id { get; private set; }
    public virtual string Name { get; set; }
    public virtual string Description { get; set; }
    public virtual decimal Price { get; set; }
    public virtual bool Visible { get; set; }
    public virtual IList<Category> Categories { get; set; }

    public Product()
    {
        Categories = new List<Category>();
    }
}

public class ProductMap : ClassMap<Product>
{
    Id(x => x.Id);
    Map(x => x.Name);
    Map(x => x.Description);
    Map(x => x.Price);
    Map(x => x.Visible);
    HasManyToMany(x => x.Categories)
      .Table("ProductsToCategories")
      .ParentKeyColumn("Product_id")
      .ChildKeyColumn("Category_id")
      .Cascade.AllDeleteOrphan();
}

public class Category
{
    public virtual int Id { get; private set; }
    public virtual string Name { get; set; }
    public virtual string Description { get; set; }
    public virtual bool Visible { get; set; }
    public virtual IList<Product> Products { get; set; }

    public Category()
    {
        Products = new List<Product>();
    }
}

public class CategoryMap : ClassMap<Category>
{
    Id(x => x.Id);
    Map(x => x.Name);
    Map(x => x.Description);
    Map(x => x.Visible);
    HasManyToMany(x => x.Products)
      .Table("ProductsToCategories")
      .ParentKeyColumn("Category_id")
      .ChildKeyColumn("Product_id")
      .Cascade.AllDeleteOrphan().Inverse();
}

with configuration,

public static void BuildFactory()
{
    _factory = Fluently.Configure()
        .Database(
            MsSqlConfiguration
                .MsSql2008
                .ConnectionString(_connectionString)
                .ShowSql()
        )
        .Mappings(m => {
            m.FluentMappings.AddFromAssemblyOf<Database>();
            m.AutoMappings.Add(
              AutoMap.AssemblyOf<Database>()
              .Where(t => t.Namespace == "FancyStore.Models.Catalog"));
        })
        .ExposeConfiguration(SetConfiguration)
        .BuildConfiguration()
        .BuildSessionFactory();
}

Ajw 2010-01-18 02:26:51

Answer 4

A:

@Matt Briggs, I've figured it out. You have to set one relationship as Inverse() and save the other entity, add references to both entities (prod.Categories.Add() + cat.Products.Add()) and commit the transaction. Unless you commit the query for the join table won't be generated. – HeavyWave May 13 at 12:43

Matt Briggs 2010-09-17 00:59:37

ansaurus

tags:

views:

answers:

Fluent NHibernate (with automapping) not saving join table values in many-to-many

related questions