If you have a column in your database which may only contain the value 0 or 1 (i.e. a bit value), you probably want to map it to the boolean static type in your entity, rather than an integer. This could be the case for smallint, tinyint(1), int(1), boolean columns, etc. I found two suggestions… read more
Did you know that you can return a boolean value from a Spring Data JPA query? For instance, you may want to know whether or not an entity (i.e. database row) exists with a given value for a field. Surely one could simply return the row count and check if it is larger than zero, but… read more
With object-relational mapping (ORM) tools such as Hibernate, one usually modifies entities by first fetching them from the database, modifying some fields, and then persisting the entities again. This is a good approach in many cases, but in some scenarios this may not be desirable. For instance, if you want to update a collection of entities (i.e.… read more
I recently had a problem with one of my Spring Data JPA queries; for some reason, I was getting the following exception. query specified join fetching, but the owner of the fetched association was not present in the select list This seemed strange, because I had written a standard JPQL/HQL query that I knew worked.… read more