Hibernate查询与别名 [英] Hibernate query with an alias

问题描述

  session.createCriteria（Composed.class，main）
 .createAlias（ main.id.branch，b1）
 .add（Restrictions.eq（b1.owner，user））
 .list（）; 
  

？相应的HQL工作正常

  String hql =select main from Composed as main
 +left join main。 id.branch as b1 where b1.owner =？; 
 session.createQuery（hql）
 .setInteger（0，user.id（）。intValue（））
 .list（）; 
  

从Criteria中， Hibernate不创建连接并使用 where b1x1_.owner_id =？，但在任何地方都没有 b1x1 _ ，所以失败时显示could not prepare statement。

这些类很平凡

  @Entity class Composed {
 @ Id ComposedId id; //也试过@EmbeddedId 
 ...不相关的东西
} 
 
 @Embeddable class ComposedId {
 @ManyToOne（optional = false）分支分支; 
 ...不相关的东西
} 
 
 @Entity类分支{
 @Id整数ID; 
 @ManyToOne（可选= false）用户所有者; 
 ...不相关的东西
} 
 
 @Entity类用户{
 @Id整数ID; 
 ...不相关的东西
} 
  

更新

我终于创建了 SSCCE 并提交了问题

一>。对不起，如果没有SSCCE，这是很难重现。

解决方案

我没有尝试，但也许创建两个左连接的别名可以帮助您。我的意思是：

  session.createCriteria（Composed.class，main）
 .createAlias（main。 id，id1，JoinType.LEFT_OUTER_JOIN）
 .createAlias（id1.branch，b1，JoinType.LEFT_OUTER_JOIN）
 .add（Restrictions.eq（b1.owner，user ））
  

希望它有帮助！

What's wrong with

session.createCriteria(Composed.class, "main")
.createAlias("main.id.branch", "b1")
.add(Restrictions.eq("b1.owner", user))
.list();

? The corresponding HQL works fine

String hql = "select main from Composed as main"
        + "left join main.id.branch as b1 where b1.owner = ?";
session.createQuery(hql)
.setInteger(0, user.id().intValue())
.list();

From the Criteria, Hibernate creates no join and uses where b1x1_.owner_id=?, but there's no b1x1_ anywhere, so it fails with "could not prepare statement".

The classes are rather trivial

@Entity class Composed {
    @Id ComposedId id; // also tried @EmbeddedId
    ... irrelevant stuff
}

@Embeddable class ComposedId {
    @ManyToOne(optional=false) Branch branch;
    ... irrelevant stuff
}

@Entity class Branch {
    @Id Integer id;
    @ManyToOne(optional=false) User owner;
    ... irrelevant stuff
}

@Entity class User {
    @Id Integer id;
    ... irrelevant stuff
}

Update

I've finally created an SSCCE and filed an issue. Sorry for the confusing question, without the SSCCE, it's rather hard to reproduce.

解决方案

I didn't try but maybe creating two aliases with left join helps you. I mean this:

session.createCriteria(Composed.class, "main")
   .createAlias("main.id", "id1", JoinType.LEFT_OUTER_JOIN)
   .createAlias("id1.branch", "b1", JoinType.LEFT_OUTER_JOIN)
   .add(Restrictions.eq("b1.owner", user))

Hope it helps!

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