Hibernate IN子句有多列 [英] Hibernate IN Clause with multiple columns

问题描述

需要知道如何构建一个Hibernate查询，它获取匹配包含多个列值的 IN 子句的结果。

<例如，

  Query query = session.createQuery（from entity e where（e.abc，e.xyz）in （：list））; 
 query.setParameterList（list，list）; 
  

这里 list 是一个2D数组，可以包含原始类型的基本包装器对象，例如 Integer ， String 等。

这是可能的吗？

解决方案

基本上，我们需要在我们需要查询的一组列中创建一个Hibernate组件（读@Embeddable对象），并将它嵌入到主实体中。

组可以合并如下：

  @Embeddable 
 public class CompositeColumns {
 private String col1; 
私人字符串col2; 
 
 // Hibernate需要空构造函数进行实例化
 public CompositeColumns（）{
} 
 
 public CompositeColumns（String col1，String col2）{ 
 this.col1 = col1; 
 this.col2 = col2; 
 
 
 @Column（name =COL1）
 public String getCol1（）{
} 
 ... 
 .. 。
 //其余的getter和setters 
} 
  

---

将以上内容嵌入您的主实体类中，如下所示：

  @Entity 
 public class MyEntity {
 @Id 
 private Integer id; 
私人字符串col3; 
私人字符串col4 
 @Embedded 
私人CompositeColumns pairedCol1Col2; 
 ... 
 ... 
 // Getters Setters 
 
} 
  

---

查询如下所示：

  List< CompositeColumns> cols = //获取CompositeColumns类型的列表
 
 Query query = session.createQuery（from MyEntity where pairedCol1Col2 in（：list））; 
 query.setParameterList（list，list）; 
  

这样做。

注意：我在Oracle数据库上运行它

Need to know how to construct a Hibernate Query which fetches results matching an IN clause containing multiple column values.

e.g.,

Query query=session.createQuery( "from entity e where (e.abc, e.xyz) in (:list)" );
query.setParameterList( "list", list );

Here list would be a 2D array that could contain basic wrapper objects for primitive types e.g., Integer, String etc.

Is this possible?

解决方案

Putting down here how I implemented this. Basically we need to make a Hibernate Component (read @Embeddable object) out of the set of columns we need to query on and embed it in the main Entity.

The group of columns can be combined as below:

@Embeddable
public class CompositeColumns{
  private String col1;
  private String col2;

  //Empty constructor is required by Hibernate for instantiation
  public CompositeColumns(){
  }

  public CompositeColumns(String col1, String col2){
            this.col1 = col1;
            this.col2 = col2;
      }

  @Column(name="COL1")
  public String getCol1(){
  }
  ...
  ... 
  //Rest of getters and setters
}

---

Embed the above in your main entity class as below:

@Entity
public class MyEntity{
 @Id
 private Integer id;
 private String col3;
 private String col4
 @Embedded
 private CompositeColumns pairedCol1Col2;
 ...
 ...
 //Getters Setters

}

---

The query would then look as below:

List<CompositeColumns> cols = //get a list of CompositeColumns type

Query query=session.createQuery( "from MyEntity where pairedCol1Col2 in (:list)" );
query.setParameterList( "list", list );

This does the job.

Note: I ran this on an Oracle database

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