Using the following url in the data source properties
using the dataSource.url=jdbc:log4jdbc:hsqldb:mem:db_integra tion;sql.syntax_mys=true
solved the isue.
But I still have one question: how come using HSQLDB withOUT any MySQL property works fine when accessed through an Hibernate DAO and not when accessed through a JPA repository ?
The point of testing either against a MySQL database or an HSQLDB database is that these two being a bit different, I can make sure my code is portable. Now if I tell one, the HSQLDB database to behave as the other then there is less point in using it.
It's like HSQLDB behaves in a MySQL-like way when accessed through an Hibernate DAO but behaves in a non-MySQL-like way when accessed through a JPA repository.
By DAO I referred to my own layer of data access code. Using Hibernate works just fine against HSQLDB without the additional url property. But using JPA requires the url property apparently. It's too bad.