hql-like“；选择“新建构造函数”；在Hibernate中，执行多个sql

当我将hql中的构造函数用作blow时：

String jpql=“从a、b中选择前10个新结果（a、b），其中a.id=b.id” Query Query=entityManager.createQuery（jpql）； 控制台打印出20条sql语句。不像我预期的那样一条都没有。但是当构造函数只包含表a和表B的文件时，它只执行一条sql。我想知道为什么会这样。谢谢你的帮助

抱歉，不清楚，以下是一些详细信息：

List list = baseDao.findListByQL("select new List(a,b) from A a,B b where a.id=b.id");

方法“findListByQL”刚刚调用了一个方法，使用“Query Query=entityManager.createQuery（jpql）；”来获得一些结果

和hibernate打印一些SQL，如下所示：

Hibernate: select a0_.id as col_0_0_, b1_.id as col_1_0_ from dbo.A a0_, dbo.B b1_ where a0_.id=b1_.id
Hibernate: select a0_.id as id103_0_, a0_.name as name103_0_ from dbo.A a0_ where a0_.id=?
Hibernate: select b0_.id as id106_0_, b0_.score as score106_0_ from dbo.B b0_ where b0_.id=?
Hibernate: select a0_.id as id103_0_, a0_.name as name103_0_ from dbo.A a0_ where a0_.id=?
Hibernate: select b0_.id as id106_0_, b0_.score as score106_0_ from dbo.B b0_ where b0_.id=?
Hibernate: select a0_.id as id103_0_, a0_.name as name103_0_ from dbo.A a0_ where a0_.id=?
Hibernate: select b0_.id as id106_0_, b0_.score as score106_0_ from dbo.B b0_ where b0_.id=?
Hibernate: select a0_.id as id103_0_, a0_.name as name103_0_ from dbo.A a0_ where a0_.id=?
Hibernate: select b0_.id as id106_0_, b0_.score as score106_0_ from dbo.B b0_ where b0_.id=?
Hibernate: select a0_.id as id103_0_, a0_.name as name103_0_ from dbo.A a0_ where a0_.id=?
Hibernate: select b0_.id as id106_0_, b0_.score as score106_0_ from dbo.B b0_ where b0_.id=?
Hibernate: select a0_.id as id103_0_, a0_.name as name103_0_ from dbo.A a0_ where a0_.id=?
Hibernate: select b0_.id as id106_0_, b0_.score as score106_0_ from dbo.B b0_ where b0_.id=?
Hibernate: select a0_.id as id103_0_, a0_.name as name103_0_ from dbo.A a0_ where a0_.id=?
Hibernate: select b0_.id as id106_0_, b0_.score as score106_0_ from dbo.B b0_ where b0_.id=?
Hibernate: select a0_.id as id103_0_, a0_.name as name103_0_ from dbo.A a0_ where a0_.id=?
Hibernate: select b0_.id as id106_0_, b0_.score as score106_0_ from dbo.B b0_ where b0_.id=?
Hibernate: select a0_.id as id103_0_, a0_.name as name103_0_ from dbo.A a0_ where a0_.id=?
Hibernate: select b0_.id as id106_0_, b0_.score as score106_0_ from dbo.B b0_ where b0_.id=?

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但是，当“new List”构造函数使用一些字段属性（如“new List（a.name，b.score）”）时，它只打印一条sql。

当您执行HQL时，如：

select new List(a,b) from A a,B b where a.id=b.i

select new List(a.name,b.score) from A a,B b where a.id=b.i

您将返回整个实体A和B。即使看不到这些实体的代码，它们也可能映射了一些渴望的关系，如

@ManyToOne

或

@OneToOne

在渴望的关系中，每次您点击具有此关系的实体时，它都会带来关联的实体。这可以解释为什么会有多个SQL

但是，当您执行HQL时，如：

select new List(a,b) from A a,B b where a.id=b.i

select new List(a.name,b.score) from A a,B b where a.id=b.i

您只返回了一些字段。在本例中，由于您没有使用实体类，因此“忽略”了急切关系

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如果您提供有关实体类别A和B的更多详细信息，我们可以指定您实体中这种行为的确切解释以及如何改变这种行为。

您的问题有点不清楚，请将这两个查询与各自的结果一起发布。另外，

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在JPQL中不是保留关键字&您不是在创建本机查询，这是您的工作代码。谢谢您的关注。我添加了一些细节，希望足够清楚。