Hibernate JPQL - 在地图关联错误中查询 KEY()

发布于 2024-12-05 08:25:57 字数 1822 浏览 1 评论 0原文

我正在尝试创建一个 JPQL 查询，该查询应该从其映射关联之一获取实体和键，但我收到了一个奇怪的错误。

我的设置是使用 Hibernate (3.5) 实现的 JPA2。

模型如下：

我有一个 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)
protected Long id;

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

//... getters 和 setters follow

及其关联实体：

@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 和 setters follow

现在我想，根据“Mastering JPA2...”一书，我可以执行 JPQL，例如：

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

但这一切都会给我带来一个奇怪的错误：

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)...

有人可以告诉我我使用的 JPQ 是否错误，如果是，正确的可能是什么除了获取实体并且仅获取其地图关联之一的键之外，还有其他选择吗？

原文

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?

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