Hello, When a class (Product) have 2 collections (I only checked with reversed mapping) of concrete objects (one of MecanicalFeature and one of ElectricalFeature) inheriting from a common class (Feature), finding an existing Product fails (return null).
Here is a class diagram : http://www.plantuml.com/plantuml/png/SoWkIImgAStDuKhEIImkLWWeoayfJIw1yjnI4qjAYrAXFD_KvCIypEJ475HXrvpKv98YP74kT9KAkherTd3J81fmIaET01IqKr3IKbB0CCnAGIaN9bQiXA4UOZoQXbIm85I7GsfU2j3B0000 Here is the ER diagram http://www.plantuml.com/plantuml/png/RSvFIyCm60Rm-_ifNkTb0SVk4iF6ia9FokpE8pNlR31fI_v0Y_ZTLLhR2iijvFSyUNOXAX-Jit2dwMfgmgXAI-kEuPjL8M27dEEwUBZFiltFOIZ4H5jldFBzvOFwtm0l1K-Yuzia-BQSsRNnPDxhYPa5Cm8gemaTnQhHORY4I9wQsBSK08OzBwTdUJuK33y1__sRImPV8ygE--9yEjv6Y39_FG0kv_pLNeQMCO-RZS3nvN4rawTShc17jKxEVWC0 The entityManager.find generates the following SQL (I replaced useless columns by *) : SELECT t0.*, t3.* FROM Product t0 LEFT OUTER JOIN Feature t3 ON t0.id = t3.PRODUCT_ID WHERE (t3.disc IS NULL OR t3.disc IN ('Mecanical')) AND t0.id = 0 ORDER BY t3.PRODUCT_ID ASC The eager fetching on those collections consider only one collection or only one type of concrete class. A solution would be to have, in the IN clause the list of all possible subtypes of all collections mapped on the target table (‘Mecanical’, ‘Electrical’). Regards, Provenance : Courrier<https://go.microsoft.com/fwlink/?LinkId=550986> pour Windows 10
