GORM能否复制整个对象？ [英] can GORM duplicate whole object?

问题描述

我们使用grails开发一些web应用程序
对于具有子类的Domain类，我想知道是否可以复制包含属于Parent的所有子对象的整个对象？

谢谢

解决方案

如评论中所述，您可以使用 clone 方法。 然而，如果你不想混淆gorm api，一个非常简单的解决方案就是分离现有的对象，然后保存它。请注意，这不会执行 deepClone 。

步骤：

1. 清空ID。


2. 更新副本中不同的字段。
   
3. 分离对象


4. 
   




代码示例，假设一个域类 Region ，它有一个唯一的名称属性，需要在保存前更改：

< pre $ def copyRegion（Region region，String newName）{
region.id = null
region.name = newName
region.discard（）
if（region.save（））{
//句柄成功
} else {
//句柄错误
}
}


另见。




we are using grails to develop some web application For Domain class that have child class , I'm wondering if we can duplicate whole object including all child object that belong to Parent ?

Thank you

解决方案

As given in the comments, you can extend gorm with a clone method.

However, a very simple solution if you don't want to mess with the gorm api is to detach the existing object and just "resave" it. Note that this won't perform a deepClone.

Steps:

1. Null the id.
2. Update fields that should differ in the copy.
3. Detach the object in question.
4. Save it.

Code example, assuming a domain class Region which has a unique name property that needs to change before saving:

def copyRegion(Region region, String newName) {
    region.id = null
    region.name = newName
    region.discard()
    if (region.save()) {
        // handle success
    } else {
        // handle error
    }
}

See also this question about disconnecting an object.

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