NHibernate Mapping-by-code One-To-One relationship: fetch by Join?

Question

I have a table (UncommittedVideoFile) that has a strict one-to-one relationship with a different table (VideoOrImageAsset). When I load an UncommittedVideoFile, I want to load the VideoOrImageAsset in the same query via a JOIN. (Inner or left outer).

Apparently it's possible to specify fetch-by-join when you use xml mapping: https://ayende.com/blog/3960/nhibernate-mapping-one-to-one

It's also possible if you are using Fluent NHibernate: https://stackoverflow.com/a/15694723/25216

But using MappingByCode, is is possible to set a Fetch option? I can't see one anywhere.

Here is the code that I currently have. The IOneToOneMapper interface does not have a Fetch method.

classMapper.OneToOne(
    f => f.VideoOrImageAsset,
    oneToOneMapper =>
    {
        oneToOneMapper.Constrained(true);
        oneToOneMapper.ForeignKey("Id");
        oneToOneMapper.Lazy(LazyRelation.NoLazy);
    }
);

score 1 · Accepted Answer · answered Jul 14 '20 at 09:30

It's known missing mapping-by-code feature GH-2139. And it's already implemented in 5.3 (not yet released, but pretty close)

For now you can use pre-release version of 5.3 from https://www.myget.org/gallery/nhibernate (also check notes how to use it here)

NHibernate Mapping-by-code One-To-One relationship: fetch by Join?

1 Answers1