You should include cascade=”all” (if using xml) or cascade=CascadeType.ALL (if using annotations) on your collection mapping. This happens because you have a collection in your entity, and that collection has one or more items which are not present in the database. By specifying the above options you tell hibernate to save them to the database … Read more
The solution is simple, just use the CascadeType.MERGE instead of CascadeType.PERSIST or CascadeType.ALL. I have had the same problem and CascadeType.MERGE has worked for me. I hope you are sorted.
First off, some clarifications to KLE‘s answer: Unconstrained (nullable) one-to-one association is the only one that can not be proxied without bytecode instrumentation. The reason for this is that owner entity MUST know whether association property should contain a proxy object or NULL and it can’t determine that by looking at its base table’s columns … Read more
Can I see (…) the real SQL If you want to see the SQL sent directly to the database (that is formatted similar to your example), you’ll have to use some kind of jdbc driver proxy like P6Spy (or log4jdbc). Alternatively you can enable logging of the following categories (using a log4j.properties file here): log4j.logger.org.hibernate.SQL=DEBUG … Read more
The annotation @JoinColumn indicates that this entity is the owner of the relationship (that is: the corresponding table has a column with a foreign key to the referenced table), whereas the attribute mappedBy indicates that the entity in this side is the inverse of the relationship, and the owner resides in the “other” entity. This … Read more
From the community documentation: hibernate.hbm2ddl.auto Automatically validates or exports schema DDL to the database when the SessionFactory is created. With create-drop, the database schema will be dropped when the SessionFactory is closed explicitly. e.g. validate | update | create | create-drop So the list of possible options are, validate: validate the schema, makes no changes … Read more
As we can see here you have closed connection to DB in that time when you try to setString do. The way It is possible When you don’t create any connection to DB When you create but don’t open any connection to DB When you create and, even open, but, close connection before tries to … Read more
It is already a classical problem: you can’t use Hibernate 4 configuration code to configure Hibernate 5. https://stackoverflow.com/a/32711654/3405171 Just use: Configuration configuration = new Configuration().configure(); sessionFactory = configuration.buildSessionFactory(); Above code works, if you have properties in hibernate.properties. You have it in hibernate.cfg.xml. I can’t remember, probably, it will work for this situation too. Any way, … Read more
Your query looks like this: “SELECT E.username FROM MyUser E” The E.username part will return a list of username Strings. It should be From MyUser to get MyUser objects. Something like: List<MyUser> p1 =sn.createQuery(“FROM MyUser”).list();