休眠条件：左外部连接对两个表都有限制 [英] Hibernate Criteria: Left Outer Join with restrictions on both tables

问题描述

我正在做一个LEFT OUTER JOIN，但我只能对第一个表应用限制。还有一种方法适用于第二张桌子吗？

这是我的代码：

  Criteria criteria = this.crudService 
 .initializeCriteria（Applicant.class）.setFetchMode（products，
 FetchMode.JOIN）;. 
  

这有效（申请人有一个applicantName属性）：

  criteria.add（Restrictions.eq（applicantName，Markos）
  

这些作品都没有（产品具有productName属性）

  criteria.add（Restrictions.eq （productName，product1）
  

criteria.add（Restrictions.eq（products.productName product1）//产品：属性的名称
criteria.add（Restrictions.eq（Product.productName，product1）//产品：数据库表的名称

这是我收到的异常（如果我理解正确），申请人中不存在productName属性：

  EJB异常：嵌套异常是：org.hibernate.QueryException：无法解析属性：products.inventedName：org.myCompany.applicant.entity.Applicant;嵌套异常是：org .hibernate.QueryException：无法解析lve property：products.inventedName：org.myCompany.applicant.entity.Applicant 
  

我尝试过使用一个别名，但是这产生了一个INNER JOIN，而不是我想要的LEFT OUTER JOIN。

如何对两个表应用限制？

更新：

问题可能与此相同：
https://forum.hibernate.org/viewtopic.php?p=2393694

$您可以在createalias中指定左外连接...

 
  .CreateAlias（products，p，NHibernate.SqlCommand.JoinType.LeftOuterJoin）
 .Add（Restrictions.Eq（p.inventedName，inventedName））; 
  

请注意，您正在对该列进行限制，它是一个内部连接。如果您还希望没有产品的申请人，那么您也必须检查空产品。

I am doing a LEFT OUTER JOIN, but I am only able to apply Restrictions on the first table. Is there a way ti apply on the second table as well?

Here is my code:

Criteria criteria = this.crudService
        .initializeCriteria(Applicant.class).setFetchMode("products",
              FetchMode.JOIN);.

This works (applicant has an applicantName property):

criteria.add(Restrictions.eq("applicantName", "Markos")

Neither of these works (product has a productName property)

criteria.add(Restrictions.eq("productName", "product1")

criteria.add(Restrictions.eq("products.productName", "product1") // products: the name of the property criteria.add(Restrictions.eq("Product.productName", "product1") // Product: the name of the DB table

And this is the exception I am receiving saying (if I understand correctly) that the productName property does not exist in Applicant:

EJB Exception: ; nested exception is: org.hibernate.QueryException: could not resolve property: products.inventedName of: org.myCompany.applicant.entity.Applicant; nested exception is: org.hibernate.QueryException: could not resolve property: products.inventedName of: org.myCompany.applicant.entity.Applicant

I tried to use an alias, but this generated an INNER JOIN, instead of the LEFT OUTER JOIN I want.

How can I apply restrictions on both tables?

UPDATE:

Issue is probably the same as this: https://forum.hibernate.org/viewtopic.php?p=2393694

解决方案

You can specify left outer join in the createalias...

.CreateAlias("products", "p", NHibernate.SqlCommand.JoinType.LeftOuterJoin)
.Add(Restrictions.Eq("p.inventedName", inventedName));

Be aware that you are doing a left outer join with a restriction on that column...essentially making it an inner join. If you also want applicants without products then you'll have to check for null product too.

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