java - hibernate criteria group查询错误

Question

我尝试使用 Criteria 生成以下查询:

select order_number, order_date, sum(order_amount)
from st_pur_orders
group by ORDER_NUMBER,ORDER_DATE;

这是我的标准:

  Criteria cr = session.createCriteria(StPurOrders.class);
            cr.setProjection(Projections.projectionList()
                    .add(Projections.property("orderNumber"), "orderDate")
                    .add(Projections.sum("orderAmount"))
                    .add(Projections.groupProperty("orderNumber"))
                    .add(Projections.groupProperty("orderDate")));
            cr.setResultTransformer(Transformers.aliasToBean(PurOrderColl.class));
            list = cr.list();

但是在后台生成的查询是这样的:

select this_.ORDER_NUMBER as y0_, sum(this_.ORDER_AMOUNT) as y1_,
    this_.ORDER_NUMBER as y2_, this_.ORDER_DATE as y3_
from STOCK.ST_PUR_ORDERS this_
group by this_.ORDER_NUMBER, this_.ORDER_DATE;

我的问题是为什么 ORDER_NUMBER 字段被列出两次？

Answer 1

My Question is why is the ORDER_NUMBER field being listed twice?

您的条件已具有 Projections.groupProperty("orderNumber")。因此，生成的查询将在其 select 子句中包含 orderNumber。

我认为不需要显式指定 Projections.property("orderNumber")。您可以删除它并尝试一下吗？

这同样适用于使用 groupProperty(..) 指定的任何其他字段。