Null reference exception when using FetchOneToMany

[kevinsbennett]

I am getting an exception when running a OneToMany query where there are no 'many's'.

For example, I have the 2 following pocos:

[TableName("Products")]
[PrimaryKey("IDProduct")]
public partial class Product
{        
    public int IDProduct { get; set; }
    public string Name { get; set; }
    public string Description { get; set; }

    [Ignore]
    public List<ProductCategory> ProductCategories { get; set; }
}

[TableName("ProductCategories")]
[PrimaryKey("IDProductCategory")]
public partial class ProductCategory
{        
    public int IDProductCategory { get; set; }
    public int IDProduct {get; set;}
}

and here is the query I am running:

var sql = @"select Products.*, ProductCategories.* 
              from Products left join ProductCategories on Products.IDProduct =     ProductCategories.IDProduct where Products.IDProduct=@0";

product = db.FetchOneToMany<Product, ProductCategory>(
     p => p.IDProduct, 
     pc => pc.IDProductCategory, 
     sql, id)
     .FirstOrDefault();

The manyKey lambda passed in is causing the problem... when there are no ProductCategories in the database, it gets a null reference exception because null is passed in for 'pc' into the lambda. When there are ProductCategories in the database, then the query works great.

Is this a bug or am I missing something?

[schotime]

Hey Keven,

This looks like a bug from first look. It is related to the change that was done so that if you are doing a many to one, and the one has all null values then the object will be set to null.

I will have a look at it today and hopefully have a solution for it.

Cheers,
Adam

[schotime]

Hi Keven,

Check out 2.1.25-beta on NuGet and let me know if it works.

Cheers,
Adam

[kevinsbennett]

Adam,

that did the trick.

Thanks!
KB

[schotime]

Excellent.
I think in theory now the second lambda is not needed.
This was to overcome the fact that an empty object would be mapped and not a null object returned.
Adam

[enriko-riba]

Having the same problem, any new release date?
Not that I couldn't use the beta but its cleaner to have only referenced release builds

[schotime]

Can create a release today probably.
Cheers,
Adam

[schotime]

This has been release in 2.1.27.
Thanks.

[enriko-riba]

Thats great thnx!