Play 框架不提供針對某一個欄位求和方法，那麼一般出現這種情況都會去寫原生sql去執行，非常簡單：

String sql = "select sum(count) as count from book ";
Long sum;
Object sumFlag = JPA.em().createNativeQuery(sql).getSingleResult();

嗯，就這樣，此方法同樣適合其他返回一個欄位的操作

jpa獲取集合(如果你想只要自己想要的欄位，那麼可以如下獲取)：
第一種：

	Query query = JPA.em().createNativeQuery("select id,name,price from book");
	//此段必加，指定返回的型別為Map
	query.unwrap(SQLQuery.class).setResultTransformer(Transformers.ALIAS_TO_ENTITY_MAP);
	List list = query.getResultList();
	for (int i = 0; i < list.size(); i++) {
		Map<String, Object> map = (Map<String, Object>) list.get(i);
		System.out.println(map.get("id"));
		System.out.println(map.get("name"));
		System.out.println(map.get("price"));
	}
 

第二種：

Query query = CurriVideo.em().createNativeQuery
        				("select "
        				+ "id               ,"
        				+ "name             ,"
        				+ "cover            ,"
        				+ "file_path        ,"
        				+ "charge           ,"
        				+ "price_money      ,"
        				+ "price_inte       ,"
        				+ "old_price_money  ,"
        				+ "old_price_inte   ,"
        				+ "null as publish_date     ,"
        				+ "null as status           ,"
        				+ "null as curri_id         ,"
        				+ "null as sort_num         "
        				+ "from curri_video",CurriVideo.class);
List<CurriVideo> list = query.getResultList();
for (CurriVideo curriVideo : list) {
	System.out.println(curriVideo.name);
	System.out.println(curriVideo.sort_num);
}
 

看實際業務來決定用哪種。
個人建議第一種，第二種有侷限性，比如實體中有一欄位為

@OneToMany
@JoinColumn(name="curri_id")
public List<Curriculum> currList;

那麼必須查詢出curri_id欄位，並且不能設定為空，違背了我們最初想要的結果。