Implement ORM from the scratch

See more:

ORM

I would like to implement ORM framework. I'm interested in loading related objects. I want to load an object and it's relation by one query. For instance: load CustomerOrder its OrderLines (CustomerOrder.OrderLines ) + CustomerOrder.OrderLines.Products. I need to join 3 tables here but need an article or book about how to transfer joined data to object. I'll implement it in c#, but mostly interested in how to transform joined table data into a graph object with complex structure. Handle loop references etc. Just need some guid how to write such functionality or reference to a topic how EF internally does it.