NHibernate LINQ Fetch() with dynamic component and relations/associations

28 views

Skip to first unread message

juanita

unread,

Apr 9, 2024, 1:50:14 PMApr 9

to nhusers

What is the correct syntax for eager fetching with LINQ queries involving dynamic component and related entities?

NHibernate supports dynamic components, where dynamic/additional properties are stored in an IDictionary property of the POCO (e.g. via dynamic-component in hbm.xml). Dynamic/additional properties can be simple or relations/associations (one-to-many, many-to-one, etc.).

I know how to use LINQ queries with conditions over simple additional properties, e.g.

session.Query<Customer>().Where(c => c.DynamicProperties["DynProp"]) == "XXX")

This also works with LINQ queries over associated/related entities, e.g.

session.Query<Customer>().Where(c => ((AssocEntity)c.DynamicProperties["DynAssoc"]).Name == "XXX")

However, how would I instruct the query to fetch associated entities when they are a dynamic component part? Something like

.Fetch(p => p.DynamicProperties["DynAssoc"])

Throws the following exception:

ArgumentException: A fetch request must be a simple member access expression

Note that I do not want to change my NHibernate config to drive the eager fetching (if that is possible at all), since it should be part of the query. I need the feature as I am getting LINQ queries (from an ODATA interface) that need to be executed and specifically need the dynamic part of the component mapping.