Grails 多数据源域问题 [英] Grails multi datasource domain issue

问题描述

我有一个项目，其中的表分布在 2 个数据源之间.我正在按照 grails 文档中的 3.3.6 主题配置代码以访问表http://grails.org/doc/2.0.0.M2/guide/conf.html#dataSourcesAndEnvironments

I have a project which tables spread between 2 datasources. I'm configuring the code to access table as per 3.3.6 topic in grails documentations http://grails.org/doc/2.0.0.M2/guide/conf.html#dataSourcesAndEnvironments

似乎一切正常，但出现以下错误

Everything seems to be ok, but I got the following error

消息:创建名为transactionManagerPostProcessor"的 bean 时出错:bean 初始化失败；嵌套异常是 org.springframework.beans.factory.BeanCreationException:创建名为transactionManager"的 bean 时出错:设置 bean 属性sessionFactory"时无法解析对 beansessionFactory"的引用；嵌套异常是 org.springframework.beans.factory.BeanCreationException:创建名为sessionFactory"的 bean 时出错:调用 init 方法失败；嵌套异常是 org.hibernate.MappingException:关联引用未映射的类:br.com.fisgo.Provider

Message: Error creating bean with name 'transactionManagerPostProcessor': Initialization of bean failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'transactionManager': Cannot resolve reference to bean 'sessionFactory' while setting bean property 'sessionFactory'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sessionFactory': Invocation of init method failed; nested exception is org.hibernate.MappingException: Association references unmapped class: br.com.fisgo.Provider

由 MappingException 引起:关联引用未映射的类:br.com.fisgo.Provider

Caused by MappingException: Association references unmapped class: br.com.fisgo.Provider

知道为什么会出现此错误吗?

Any idea on why do I get this error?

问候.

我会试试的.它不会那么简单，因为公司域链接回提供商只是需要更多的努力

I'll try it out. It won't be that simple because Company domain links back to Provider It will just require more efort

class Company {
    String name
    String cnpj
    String email
    Address address
    Phone phone
    String registration
    String source

    Set provider = new HashSet<Provider>()

    static hasMany = [provider: Provider]

推荐答案

您应该使用较新的文档，例如http://grails.org/doc/latest/guide/conf.html#dataSourcesAndEnvironments

You should use newer docs, e.g. http://grails.org/doc/latest/guide/conf.html#dataSourcesAndEnvironments

您似乎正在尝试跨数据源进行链接.这是不可能的，因为每个 DataSource 都有一个单独的 SessionFactory，并且它们不能直接一起工作.当您使用 Hibernate 和 NoSQL GORM 插件时，也会发生同样的问题.

It looks like you're trying to link across datasources. This isn't possible since each DataSource has a separate SessionFactory, and they cannot work directly together. The same problem happens when you use Hibernate and a NoSQL GORM plugin.

不过你可以很容易地模仿它.给定一个需要引用 Provider 的域类 Foo，您可以保留外键并按需查找它(当您在两个域类之间加入时，这正是 Hibernate 为您所做的):

You can mimic it easily enough though. Given a domain class Foo that needs a reference to Provider, you can persist the foreign key and look it up on-demand (and this is really what Hibernate does for you when you join between two domain classes):

class Foo {
   Long providerId

   Provider getProvider() {
      providerId ? Provider.get(providerId) : null
   }
   void setProvider(Provider provider) {
      providerId = provider.id
   }
   static transients = ['provider']
}

由于 Groovy 将 getter/setter 对视为属性，因此您可以像使用真实"链接一样使用它:

Since Groovy treats getter/setter pairs as a property, you would use it like a "real" link:

def foo = ...
def bar = foo.provider.bar

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