Joining strategy in Liferay ORM

[Daniël Duwaer, geändert vor 7 Jahren.]

Given two related entities (i.e. the standard Liferay user and some custom entity which contains a reference to the user entity), can the two be joined without the use of a custom SQL query (which is database-dependent) or nested queries (which have serious performance implications on larger joins)? I.e. is it possible to use methods similar to the ones in Hibernate’s Criteria API for formulating (left) joins in order to fetch one-to-many, many-to-one or one-to-one relations? Is it possible fall back on the Hibernate technology that Liferay uses, and is it possible to reference portal entities (such as the Liferay user entity) from custom (Hibernate) entities without using separate session factories (managing separate database connection pools) for each custom portlet?