73 | Update is ignored by ObjectDBHi! Sorry for my bad english skills. When I execute fulfilOrder, only Order entity is updated in ... ; @PersistenceContext(unitName = "SMShop") private EntityManager shopdb; ... public Order fulfilOrder(Long orderID, Long userID, int itemID) { Order order = shopdb.find(Order.class, orderID); if (order |
70 | Pre-detach loading: retrieval by navigation not working in if statement-why-retrieval-by-navigation-and-access webel Dr Darren Kelly It could be some sort of JVM optimization ... system a BooleanValue wrapper is ultimately an Element that can be referenced by ID, and meets a uniform and powerful ... the whole story. webel Dr Darren Kelly By JVM optimizations I meant JIT Compiler optimizations and not |
67 | Should derived fields of an EmbeddedId be manually maintained by app code?, of type ECompoundKeyMapItem, identified by their "key" within the EContainer class. The items ... "ECompoundKeyMapSubItem", identified by their keys. The embeddedId for the item class, ECompoundKeyMapItemId ... = parent; } [ObjectDB 2.3.0_01] Unexpected exception (Error 990) Generated by Java HotSpot(TM |
67 | Grouping by date() hour(ov.created), count(ov) from ObjectView ov group by hour(ov.created) order by hour(ov.created) ASC ... have to group by date(). For few queries I was concatenating 'date' from year()-month()-day() calls ... . When you group by date() there are two days per day. I mean group by divides each day |
14 | Locking in JPA update collisions resulting from simultaneous updates to the same data by two concurrent users. Locking ... by another transaction. When using ObjectDB, optimistic locking is enabled by default and fully ... is automatically increased by one. Version numbers are managed internally but can be exposed by defining a version |
14 | JPA / JDO Class EnhancerObjectDB Enhancer is a post compilation tool that improves performance by modifying the byte code ... (and actually required by JPA but not enforced by ObjectDB) to avoid accessing persistent fields ... . by using the get and set methods). If you follow this practice only user defined persistable classes |
13 | JPA Criteria API Queries, count, sum, avg, min, max, ...). ORDER BY clause (orderBy, Order, asc, desc). The links ... , are defined by the instantiation of Java objects that represent query elements. A major advantage ... factory of criteria queries and criteria query elements. It can be obtained either by |
13 | Removed entities can be found by query in the same transactionHello, we opened a transaction, load an entity from database and removed this entity by em.remove(). Afterwards the entity can be load again by query although the resulted entity have an attribute ... in build 2.7.4_04: ObjectDB uses snapshots in order to isolate transactions, i.e. to hide |
13 | Storing JPA Entity ObjectsNew entity objects can be stored in the database either explicitly by invoking the persist method ... is committed. An IllegalArgumentException is thrown by persist if the argument is not an instance ... is thrown. The exception is thrown either by persist (if that existing entity object is currently |
13 | Lazy loading of mapped by (inverse) singular referencesObjectDB ignores lazy setting of non collection mapped by (inverse) fields and loads them always eagerly. This is allowed by JPA since lazy is only hint but it is not efficient. The reason ... , at least as hollow objects. In order to instantiate referenced objects their exact type is needed |
