NHibernate - Join

Join - Podroben članek

On the face of it, it looks like a nice way to merge tables together, but that isn’t actually the primary reason for this feature. You can use it for that, for sure, but that is mostly useful in legacy databases. In most cases, your object model should be more granular than the database model, not the other way around.

The really interesting part about this feature is that it allows us to mix & match inheritance strategies. It let us create a table per hierarchy that store all the extra fields on another table, for example. That significantly reduce the disadvantage of using a table per hierarchy or table per subclass, since we can tell very easily what is the type of the class that we are using, and act appropriately.

< join
table="tablename" (1)
schema="owner" (2)
catalog="catalog" (3)
fetch="join|select" (4)
inverse="true|false" (5)
optional="true|false"> (6)
< key ... />
< property ... />
< /join>