我自己在 GORM 中的 ID [英] my own id in GORM

问题描述

我尝试更改 grails 中的标准id":

I tried to change the standard 'id' in grails:

calls Book {
  String id
  String title

  static mapping {
    id generator:'assigned'
  }
}

不幸的是，我很快注意到这破坏了我的引导程序.而不是

unfortunately, I soon noticed that this breaks my bootstrap. Instead of

new Book (id:'some ISBN', title:'great book').save(flush:true, failOnError:true)

我不得不使用

def b = new Book(title:'great book')
b.id = 'some ISBN'
b.save(flush:true, failOnError:true)

否则我会收到必须在调用 save() 之前手动分配此类的 id"错误.

otherwise I get an 'ids for this class must be manually assigned before calling save()' error.

但到目前为止还可以.

然后我在 bookController 的保存操作中遇到了同样的问题.但这一次，变通办法没有奏效.

I then encountered the same problem in the save action of my bookController. But this time, the workaround didn't do the trick.

有什么建议吗?

我知道，我可以重命名 id，但随后我将不得不更改所有脚手架视图...

I known, I can rename the id, but then I will have to change all scaffolded views...

推荐答案

这是数据绑定的一个特性.您不希望提交的数据能够更改诸如 id 和 version 之类的托管字段，因此您使用的 Map 构造函数绑定了除这两个之外的所有可用属性(它还会忽略 class、metaClass 和其他一些的任何值.

That's a feature of databinding. You don't want submitted data to be able to change managed fields like id and version, so the Map constructor that you're using binds all available properties except those two (it also ignores any value for class, metaClass, and a few others).

所以这里有点不匹配，因为该值不是由 Hibernate/GORM 管理的，而是由您管理的.如您所见，解决方法是您需要分两步而不是一步来创建对象.

So there's a bit of a mismatch here since the value isn't managed by Hibernate/GORM but by you. As you saw the workaround is that you need to create the object in two steps instead of just one.

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