Postgresql UUID supported by Hibernate?

Now you can also use the UUID class provided by java.util.UUID which gets mapped to uuid datatype of Postgres by Hibernate without any conversions required while reading/writing from the database.

  @Id
  @GeneratedValue
  private UUID id;

The generated value is auto by default this lets your JVM define the UUID. This also allows hibernate to use the batch insert optimisation.

You can configure the database to set the UUID value. More information can be found here https://vladmihalcea.com/uuid-identifier-jpa-hibernate/

This can be solved by adding the following annotation to the UUID:

import org.hibernate.annotations.Type;
...
@Type(type="pg-uuid")
private java.util.UUID itemUuid;

As to why Hibernate doesn't just make this the default setting, I couldn't tell you...

UPDATE: There still seem to be issues using the createNativeQuery method to open objects that have UUID fields. Fortunately, the createQuery method so far has worked fine for me.

You try to persist object of type UUID, which is not hibernate-annotated entity. So the hibernate wants to serialize it to byte array (blob type). This is why you get this message 'expression of type bytea'.

You can either store UUID as blobs in database (not elegant), or provide your custom serializer (much work) or manually convert that object. UUID class has methods fromString and toString, so I would store it as String.