Question

我的MySQL查询是：

SELECT 
    c.first_name, 
    c.middle_name, 
    c.last_name, 
    s.ticker, 
    COUNT(s.ticker), 
    SUM(t.cumulative_qty), 
    SUM(cumulative_balance)
FROM client_master c, security s, transaction_master t 
WHERE c.id = t. client_master_id AND s.id = t.security_id AND t.client_master_id = 4 
GROUP BY t.security_id;

此查询返回精确结果。我想编写具有匹配结果的Hibernate Criteria。这就是我试过的：

Criteria criteria = createEntityCriteria(TransactionDetails.class, "tr")
                .createAlias("tr.client", "cl")
                .createAlias("tr.security", "se")
                .add(Restrictions.eq("cl.id", clientId))
                .setProjection(Projections.sum("tr.cumulativeQty"))
                .setProjection(Projections.groupProperty("tr.securityId"));

return  criteria.list();

但此标准仅返回List tr.securityId。我想要所有的行。我哪里错了？

Answer 1

您不能多次执行setProjection()次。您需要先创建ProjectionList，然后设置每个投影。您还需要通过在Projections.property()中指定它们来告诉您在结果集中需要哪些字段。

试试这个：

ProjectionList projList = Projections.projectionList();
projList.add(Projections.sum("tr.cumulativeQty"));
projList.add(Projections.groupProperty("tr.securityId"));

projList.add(Projections.property("firstName"));
projList.add(Projections.property("lastName"));
//add other fields you need in the projection list

Criteria criteria = createEntityCriteria(TransactionDetails.class, "tr")
                .createAlias("tr.client", "cl")
                .createAlias("tr.security", "se")
                .add(Restrictions.eq("cl.id", clientId))
                .setProjection(projList);

Answer 2

此外，您可以使用多个投影内联标准。如下所示。

Criteria criteria = createEntityCriteria(SomeClass.class)
           .createAlias(...some elias...)
           .add(Restrictions..... etc)
           .setProjection(
               Projections.projectionList()
                  .add(Projections.groupProperty("someProp1"))
                  .add(Projections.property("someProp2"))
                  .add(Projections.sum("someProp3"))
           );

如何使用Hibernate中的group by和sum投影选择多个列

2 个答案: