Hibernate HQL没有返回适当的构造函数

I have HQL query

我有HQL查询

select new PaymentType(o.paymentType.idPaymentType) from Order as o where o.user='1'

it throws following exception

它抛出异常

org.hibernate.PropertyNotFoundException: no appropriate constructor in class: PaymentType
    at org.hibernate.util.ReflectHelper.getConstructor(ReflectHelper.java:187)
    at org.hibernate.hql.classic.QueryTranslatorImpl.renderSQL(QueryTranslatorImpl.java:631)
    at org.hibernate.hql.classic.QueryTranslatorImpl.compile(QueryTranslatorImpl.java:220)
    at org.hibernate.hql.classic.QueryTranslatorImpl.compile(QueryTranslatorImpl.java:185)
    at org.hibernate.engine.query.HQLQueryPlan.<init>(HQLQueryPlan.java:77)
    at org.hibernate.engine.query.HQLQueryPlan.<init>(HQLQueryPlan.java:56)
    at org.hibernate.engine.query.QueryPlanCache.getHQLQueryPlan(QueryPlanCache.java:72)
    at org.hibernate.impl.AbstractSessionImpl.getHQLQueryPlan(AbstractSessionImpl.java:133)
    at org.hibernate.impl.AbstractSessionImpl.createQuery(AbstractSessionImpl.java:112)
    at org.hibernate.impl.SessionImpl.createQuery(SessionImpl.java:1623)

But I have declared required constructor, except of this, there are declared other tree constructors with different count and types of params, and also no params constructor.

但是我已经声明了必需的构造函数,除此之外,还声明了其他树构造函数具有不同的params数量和类型,也没有params构造函数。

public PaymentType(Integer idPaymentType) {
    this.idPaymentType = idPaymentType;
}

Edit:

public class Order  implements java.io.Serializable {


     private Integer idOrder;
     private PaymentType paymentType;
     private DeliveryType deliveryType;
     ...
}

2 个解决方案

#1

two things worth to check. 1.try use a fully qualified name of PaymentType

有两件事值得一试。 1.try使用PaymentType的完全限定名称

select new com.company.xxx.PaymentType(o.paymentType.idPaymentType)

2.also make sure the id in entity Order is int/integer rather than Long or something else.

2.还要确保实体Order中的id是int / integer而不是Long或其他东西。

#2

I have seen this exception before working with Hibernate. From what I recall, it either has to do with not having the parameter-less constructor, the parameter-less constructor not having public acccess, or your entity class not being serializable.

在使用Hibernate之前,我已经看到了这个异常。根据我的记忆,它要么与没有参数的构造函数,没有参数的构造函数没有公共访问,或者你的实体类不可序列化。

Try the following:

请尝试以下方法:

Make sure you have these constructors in PaymentType class:

确保在PaymentType类中有这些构造函数:
```
/** 
 * Default, parameter-less constructor
 */
public PaymentType() {
}
```

And also for Order:

还有订单:

/** 
 * Default, parameter-less constructor
 */
public Order() {
}

Make sure that both PaymentType and Order implement java.io.Serializable.

确保PaymentType和Order都实现了java.io.Serializable。

#1