Java Persistence.createEntityManagerFactory错误
我试着从一个视频中跟随我的老师,这是我目前的代码:Java Persistence.createEntityManagerFactory错误,java,jpa,Java,Jpa,我试着从一个视频中跟随我的老师,这是我目前的代码: public static void main(String[] args) { String jpql = "SELECT p FROM ansatt p"; EntityManagerFactory emf = Persistence .createEntityManagerFactory("ansattPersistenceUnit");
public static void main(String[] args) {
String jpql = "SELECT p FROM ansatt p";
EntityManagerFactory emf = Persistence
.createEntityManagerFactory("ansattPersistenceUnit");
EntityManager em = emf.createEntityManager();
System.out.println("Kobler til database...");
try {
TypedQuery<Ansatt> query = em.createQuery(jpql, Ansatt.class);
List<Ansatt> ansatte = query.getResultList();
for(Ansatt p : ansatte) {
System.out.println("ID: " + p.getAnsNr());
}
} finally {
em.close();
}
System.out.println("Ferdig!");
}
我缺少什么吗?好的,问题是createEntityManagerFactory中的ansattPersistenceUnit与persistence.xml中的ansattPersistenceUnit不匹配 这是必须的
<persistence-unit name="ansattPersistenceUnit" transaction-type="RESOURCE_LOCAL">
在xml文件中什么是persistence.xml?
<persistence-unit name="ansattPersistenceUnit" transaction-type="RESOURCE_LOCAL">