Question

For OneToMany relationships, play framework lets the master keep a list of slaves. A list doesn’t have a fixed size and can become very large, whereas the database row in which the master is stored is of a predetermined size. So, how does Play! framework store the list of slaves in the row containing the master?

Answer 1

Play uses hibernate to persist, so this is a hibernate question, rather than specifically Play.

Let’s say I have an Author class and a Book class, where Author has a list of Books,then the database will two tables, author and book. Where book will contain a link (author_id) to the parent.

So, hibernate stores the list in a separate list. If the list does not contain entities, so the row mapping cannot be done, I believe hibernate serialises the data as a clob, so it can store any size data.