Grails：外键作为主键？ [英] Grails: Foreign key as primary key?

问题描述

首先，我必须说我有一个现有的数据库，它不能被修改（这就是为什么我有这个问题）

我有两种情况，第一种是这样的：
在这种情况下，id（主键）也必须是外键。

  class SbPEstadoComponente {
 
 static mapping = {
 table'SB_P_ESTADO_COMPONENTE'
 version false 
 idEstadoComponenteHxPEstado column：'ID_ESTADO_COMPONENTE'
 id列：'ID_ESTADO_COMPONENTE'
} 
 
 //关系
 SbPDemora idEstadoComponenteHxPEstado 
字符串可实现的
 .. 
 .. 
 .. 
} 
  

在另一种情况下，表有3列，coluns是3个表的外键。此外，这3列必须是复合主键。

任何想法？建议吗？
非常感谢！

解决方案

在您的子类的映射中，您需要 id composite： ['fkey1'，'fkey2'] 和 implements Serializable

你做一个 get 你将需要填充所有组合键值

first of all i have to say that i have an existing database that it can not be modify (that´s why i am having this problem)

I have two cases, the first one is this: In this case the id (primary key) must be a foreign key as well. The code that i put, it doesn´t work.

class SbPEstadoComponente {

    static mapping = {
         table 'SB_P_ESTADO_COMPONENTE'         
         version false
         idEstadoComponenteHxPEstado column:'ID_ESTADO_COMPONENTE'
     id column:'ID_ESTADO_COMPONENTE'
    }

    // Relation
    SbPDemora idEstadoComponenteHxPEstado
    String facturable
    ..
    ..
    ..
}

In the other case the table has 3 columns, that coluns are foreign key to 3 tables. Also those 3 columns have to be a composite primary key.

Any ideas? sugestions? Thanks a lot !!

解决方案

In your child class's mapping you need id composite: ['fkey1', 'fkey2'] and implements Serializable

Note that when you do a get you will need to populate all the composite key values

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