Hibernate JPQL - 在地图关联错误中查询KEY（） [英] Hibernate JPQL - querying for KEY() in Map association error

问题描述

我试图创建一个JPQL查询，该查询应该从一个地图关联中获取一个实体和关键字，并且出现bizzare错误。

我的设置是JPA2使用Hibernate（3.5）实现。

模型如下：

I有一个Department实体bean，例如：

  @Entity 
  

public class Department {

  @Id 
 @SequenceGenerator name =DEPARTMENT_ID_GENERATOR，sequenceName =department_sequence，allocationSize = 100）
 @GeneratedValue（strategy = GenerationType.SEQUENCE，generator =DEPARTMENT_ID_GENERATOR）
 @Column（unique = true，nullable = false） 
保护长ID; 
 
 @OneToMany（fetch = FetchType.EAGER）
私人地图< String，Phone> phones = new HashMap< String，Phone>（）; 
  

// ... getters和setters关注

以及它的关联实体：

  @Entity 
  

公共类电话{

  @Id 
 @SequenceGenerator 
 @GeneratedValue（strategy = GenerationType.SEQUENCE，generator =PHONE_ID_GENERATOR）
 @Column（unique = true，nullable = false）$ name =PHONE_ID_GENERATOR，sequenceName =phone_sequence 
保护长ID; 
私人诠释数字; 
  

// ... getters和setters关注

现在我想，按照掌握JPA2 ...的书，我可以做一个JPQL，例如：

  String queryString2 =SELECT d，KEY（p）FROM Department d JOIN d.phones p WHERE p ='internal'; 
  

但是这一切都让我感到一阵惊愕：

  java.lang.IllegalStateException：节点没有数据类型：org.hibernate.hql.ast.tree.MethodNode 
   
 $ b 
  -  [METHOD_CALL] MethodNode：'（'
 +  -  [METHOD_NAME] IdentNode：'KEY'{originalText = KEY} 
  -  [EXPR_LIST] SqlNode：'exprList'
  -  [ALIAS_REF] IdentNode：'phone2_.id'{alias = p，className = model.Phone，tableAlias = phone2 _} 
  at org.hibernate.hql.ast.tree.SelectClause.initializeExplicitSelectClause（SelectClause.java:156）... 
  
有人可以告诉我，我使用的JPQ是否是错误的，如果是这样的话，那么获取实体和仅从其地图上的密钥您的语法是正确的，这是因为地图的KEY& VALUE没有实现：
 
解决方案
 a href =https://hibernate.onjira.co m / browse / HHH-5396rel =nofollow> https://hibernate.onjira.com/browse/HHH-5396 我不知道其他查询。
 
I'm trying to make a JPQL query that should fetch an entity and the keys from one of its map associations, and I'm getting a bizzare error.

My setup is JPA2 using the Hibernate (3.5) implementation.

The model is as follows:

I have a Department entity bean such as:
@Entity
public class Department {
@Id
@SequenceGenerator(name = "DEPARTMENT_ID_GENERATOR", sequenceName="department_sequence", allocationSize=100)
@GeneratedValue(strategy=GenerationType.SEQUENCE, generator = "DEPARTMENT_ID_GENERATOR")
@Column(unique = true, nullable = false)
protected Long id;

@OneToMany(fetch=FetchType.EAGER)
private Map<String,Phone> phones = new HashMap<String, Phone>();
//... getters and setters follow

and it's associated entity :
@Entity
public class Phone {
@Id
@SequenceGenerator(name = "PHONE_ID_GENERATOR", sequenceName="phone_sequence", allocationSize=100)
@GeneratedValue(strategy=GenerationType.SEQUENCE, generator = "PHONE_ID_GENERATOR")
@Column(unique = true, nullable = false)
protected Long id;
private int number;
//... getters and setters follow

Now I thought, as per the "Mastering JPA2..." book, that I could do a JPQL such as:
String queryString2 = "SELECT d, KEY(p) FROM Department d JOIN d.phones p WHERE p='internal'";
but all this gets me a bizzare error:
java.lang.IllegalStateException: No data type for node: org.hibernate.hql.ast.tree.MethodNode 
-[METHOD_CALL] MethodNode: '('
    +-[METHOD_NAME] IdentNode: 'KEY' {originalText=KEY}
    -[EXPR_LIST] SqlNode: 'exprList'
       -[ALIAS_REF] IdentNode: 'phone2_.id' {alias=p, className=model.Phone, tableAlias=phone2_}
at org.hibernate.hql.ast.tree.SelectClause.initializeExplicitSelectClause(SelectClause.java:156)...
Can someone please tell me if the JPQ I'm using is wrong, and if so, what might be a correct alternative to getting an entity and ONLY the keys from one of its map associations?
解决方案
Your syntax is correct, this is because KEY & VALUE for maps are not implemented:
https://hibernate.onjira.com/browse/HHH-5396 I am not aware of alternative query.

                        
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