Hibernate needs to be able to compare and serialize identifiers. So the identifier class must be serializable, and override hashCode() and equals() consistently with the database’s notion of composite key equality. If you have a composite id mapped as properties of the entity, the entity itself is the identifier. A second approach is called a … Read more
Just update your trigger to only fire when not given an id. create or replace trigger sa.my_trigger before insert on sa.my_table for each row when (new.id is null) begin select sa.my_sequence.nextval into :new.id from dual; end;
There are two levels of caches: 1st level is the EntityManager’s own cache. You can either refresh on one entity and it will be reloaded form the database, or you can clear the entity manager itself, in which case all entities are removed from the cache. There is no way with JPA to evict only … Read more
One way to rename all tables at once, is to implement your own namingStrategy (implementation of org.hibernate.cfg.NamingStrategy). The NamingStrategy used is specified within persistence.xml by <property name=”hibernate.ejb.naming_strategy” value=”com.example.MyNamingStrategy” />
You can monitor your connection pool(s) via JMX. From the documentation: Configuring and Managing c3p0 via JMX If JMX libraries and a JMX MBeanServer are available in your environment (they are include in JDK 1.5 and above), you can inspect and configure your c3p0 datasources via a JMX administration tool (such as jconsole, bundled with … Read more
I had a similar problem and found this information (deeper explained in here). Adding this property into my persistence.xml file fixed the issue: <property name=”hibernate.id.new_generator_mappings” value=”false” />
maybe because you are using MYSQL5DIALECT there’s a Postgres Dialect just used post it like this and for the improved naming strategy use EJB3 like Spring boot JPA insert in TABLE with uppercase name with Hibernate spring.jpa.database-platform=org.hibernate.dialect.PostgreSQLDialect hope it works for you
I tried few versions based on Array Type introduced by JDBC4 : How can I set a String[] parameter to a native query?. Problem is also Hibernate (even in last version 4.3.1.final) does not work with this new features and gave me following error message Could not determine a type for class: org.postgresql.jdbc4.Jdbc4Array So I … Read more
Actually, according to the JPA specification it is forbidden to change a primary key: The application must not change the value of the primary key[8]. The behavior is undefined if this occurs.[9] (from EJB 3 persistence (JPA) specification, paragraph 2.1.4)
The code snippet you showed is what you need. Just use your existing configuration instead of creating a new one. If it is not you who instantiates the configuration (but, for example, spring), you’d need to extend the class that creates it.