Hey everyone, I’m new to persistence / hibernate and I need your help.
Here’s the situation. I have a table that contains some stuff. Let’s call them Persons.
I’d like to get all the entries from the database that are in that table.
I have a Person class that is a simple POJO with a property for each column in the table (name, age,..)
Here’s what I have :
Query lQuery = myEntityManager.createQuery(“from Person”)
List personList = lQuery.getResultList();
However, I get a warning saying that this is an unchecked conversion from List to List
I thought that simply changing the code to
Query lQuery = myEntityManager.createQuery(“from Person”)
List personList = (List)lQuery.getResultList();
would work.. but it doesn’t.
Is there a way to do this ? Does persistence allow me to set the return type of the query ? (Through generics maybe ? )
解决方案
As a newcomer to JPA was taking this as the definitive answer but then I found a better one via this question: Why in JPA EntityManager queries throw NoResultException but find does not?
Its as simple as as using TypedQuery instead of Query e.g.:
TypedQuery lQuery = myEntityManager.createQuery(“from Person”, Person.class);
List personList = lQuery.getResultList();