如何将myBatis结果映射到多个对象? [英] How to map a myBatis result to multiple objects?

问题描述

在myBatis 3中是否可以将单个结果映射到多个对象，以确保所有对象都引用同一实例?有没有我可以参考的例子?

Is it possible in myBatis 3 to map a single result to multiple objects, ensuring that the objects all reference the same instance? Is there an example of this I could reference?

已更新以添加更多详细信息:

例如，假设我在数据库中存储有关我的应用程序的Contact的信息.我想知道是否可以使用myBatis将联系人的同一实例映射到一个Listing类，该类包含一个Contact:

For instance, let's say I store information regarding Contacts for my application in my DB. I want to know if it's possible to use myBatis to map the same instance of a contact to, say, a Listing class, which holds a Contact:

public class Listing {
    private Contact myContact;
    //getters & setters...
}

以及ContactsHolder类，该类也包含一个Contact:

as well as to a ContactsHolder class, which also holds a Contact:

public class ContactsHolder {
    private Contact aContact
    //getters & setters...
}

我需要由myBatis映射到Listing和ContactsHolder类的对象成为同一实例.这可能吗?

I need the object that is mapped by myBatis to both the Listing and ContactsHolder classes to be the same instance. Is this possible?

推荐答案

否，MyBatis无法使用标准结果映射做到这一点. (至少据我所知).您可以选择联系人"对象，然后手动构建一个Listing和ContactsHolder，两者都引用该联系人.

No, MyBatis isn't able to do that with standard result mapping. (at least to my knowledge). You could select the "Contact" object, then build a Listing and ContactsHolder manually with both of them referencing the Contact.

或实现自定义ResultSetHandler.

Or implement a custom ResultSetHandler.

这是一种特殊的请求，我不确定为什么要在两个对象之间共享相同的实例.这可能就是为什么MyBatis 3中不存在类似功能的原因.

It's kind of a peculiar request, I'm not sure why you want the same instances shared across two objects like that. That's probably why no feature like this exists in MyBatis 3.

这篇关于如何将myBatis结果映射到多个对象?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！