Hibernate标准内部连接来选择 [英] Hibernate criteria Inner join to select

问题描述

我必须将下一个表达式转换为hibernate标准api：

  select * from games gs 
 INNER JOIN （从gg 
中选择gg.ID，gg.CODE，max（gg.DATE）max_date，其中gg.player_id = 1组由gg.ID，gg.CODE）ss 
 on gs.CODE = ss.CODE 
和gs.ID = ss.ID 
和gs.DATE = ss.max_date 
和gs.player_id = 1 
  

我该怎么做？我可以单独创建内部和外部标准，但不知道如何加入它们：

  DetachedCriteria innerCriteria = DetachedCriteria。 forClass（Games.class，gg）; 
 innerCriteria.add（Restrictions.eq（playerId，1））; 
 ProjectionList projectionList = Projections.projectionList（）; 
 projectionList.add（Projections.groupProperty（id））; 
 projectionList.add（Projections.groupProperty（code））; 
 projectionList.add（Projections.max（date））; 
 innerCriteria.setProjection（projectionList）; 
  

...

  Criteria criteria = getSession（）。createCriteria（Games.class，gs）; 
 criteria.add（Restrictions.eq（playerId，1））; 
 criteria.setProjection（Projections.id（））; 
 criteria.list（）; 
  

解决方案

Hibernate不支持<$ c $中的子查询c>来自子句。从 Hibernate 4.3文档：
$ b

请注意，HQL子查询只能出现在select或
子句中。

有一个待处理功能请求为此。

您必须重写查询才能避免这种情况，或者使用原生查询。

I have to translate the next expression into hibernate criteria api:

select * from games gs
INNER JOIN (select gg.ID, gg.CODE, max(gg.DATE) max_date from games gg 
where gg.player_id = 1 group by gg.ID, gg.CODE) ss
 on gs.CODE = ss.CODE
 and gs.ID = ss.ID
 and gs.DATE = ss.max_date
 and gs.player_id = 1

How can I do it? I'm able to create inner and outer criteria separetely, but have no idea how to join them:

    DetachedCriteria innerCriteria = DetachedCriteria.forClass(Games.class, "gg");
    innerCriteria.add(Restrictions.eq("playerId", 1));
    ProjectionList projectionList = Projections.projectionList();
    projectionList.add(Projections.groupProperty("id"));
    projectionList.add(Projections.groupProperty("code"));
    projectionList.add(Projections.max("date"));
    innerCriteria.setProjection(projectionList);

...

    Criteria criteria = getSession().createCriteria(Games.class, "gs");
    criteria.add(Restrictions.eq("playerId", 1));
    criteria.setProjection(Projections.id());
    criteria.list();

解决方案

Hibernate does not support subqueries in the from clause. From the Hibernate 4.3 documentation:

Note that HQL subqueries can occur only in the select or where clauses.

There is a pending feature request for this.

You'll have to rewrite the query to avoid that, or use native queries.

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