/*
    查询全部
        jqpl：from com.study.pojo.Customer
        sql: select * from cst_customer
     */
    @Test
    public void testFindALL(){
        EntityManager entityManager = JpaUtils.getEntityManager();
        EntityTransaction tx = entityManager.getTransaction();
        tx.begin();

        //查询全部
        String sql = "from com.study.pojo.Customer";
        Query query = entityManager.createQuery(sql);

        //发送查询，并封装结果集
        List list = query.getResultList();

        for (Object object : list) {
            System.out.println(object);
        }

        tx.commit();
        entityManager.close();
    }

使用全限定类名和类名都可以
String sql = "from Customer" 也可以