Slapper behavior for dynamic object's child objects

[digaomatias]

In my application we have a scenario where the dynamic objects returned from the query can have a null child.

Consider the user object being like this:

public class User 
{
    public int Id { get; set; }
    public string Name { get; set; }
    public Address Address { get; set; }
}

For example, if I do a query to retrieve one user and it doesn't have an address yet:

SELECT 
    U.Id, 
    U.Name, 
    U.Address_Id 
FROM Users U

This is the dynamic object returned:

{{ DapperRow, Id = '1', Name = 'Dummy User', Address_Id = NULL }}

What happens here when I use AutoMapper.MapDynamic(result) is that the User object created contains an empty instance of Address. Slapper maps the null Address_Id into an empty instance of Address with Id=0.
This could cause errors if after retrieving the object from the database, we try to save it back. It would have a reference to an object with id=0, the update on the database would break with foreign key constraint.

Is there a way to tell Slapper to not map null values to empty child objects? I would prefer to map null instead.

[rstraszewski]

I have exactly the same problem. Dapper built-in mapping is working in a way, that if splitting property is null, the whole object is null I think. Here I have object filled with nulls, which will create errors. It would be nice to set child object to null, if id is null for example... But it seems, that pull request #28 will solve my problem.

[odelvalle]

pull request #28 merged with Master