Mongodb 在Grails中是否可以加入mongo和mysql域？

我有一个域使用MySQL db，另一个域使用MongoDB。我能加入他们吗

例如：

上诉mongo域名

class Appeal {

    static mapWith = "mongo"

    Organization organization <=== MySQL domain
    ...
}

---

没有，但你可以近似计算。在两个不同的关系数据库中连接两个表也会遇到同样的问题-每个表都有自己的SessionFactory，并且Hibernate或GORM不支持跨数据库或数据存储连接

若要进行近似计算，请存储其他表/文档的主键，并使用瞬态方法为您检索实例。这基本上就是Hibernate为您所做的——它存储外键值并根据需要自动加载实例

class Appeal {

    static mapWith = "mongo"

    void setOrganization(Organization organization) {
        organizationId = organization.id
    }
    Organization getOrganization() {
        organizationId ? Organization.get(organizationId) : null
    }
    static transients = ['organization']

    Long organizationId
    ...
}

使用这种方法，您的代码将非常类似于两个表位于同一数据库中时的样子。当您访问该组织时，将使用以前保存的id从数据库中检索该组织

组织属性必须是暂时的，因为这样匹配的get/set对将被视为持久属性，正如您所看到的，这将失败。应该只保留id

Error initializing the application: 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 '$primaryTransactionManager' while setting constructor
argument with key [0]; nested exception is
org.springframework.beans.factory.BeanCreationException: Error
creating bean with name '$primaryTransactionManager': 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: lc.itgroup.education.dao.Appeal
    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 '$primaryTransactionManager' while setting constructor
argument with key [0]; nested exception is
org.springframework.beans.factory.BeanCreationException: Error
creating bean with name '$primaryTransactionManager': 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: lc.itgroup.education.dao.Appeal

class Appeal {

    static mapWith = "mongo"

    void setOrganization(Organization organization) {
        organizationId = organization.id
    }
    Organization getOrganization() {
        organizationId ? Organization.get(organizationId) : null
    }
    static transients = ['organization']

    Long organizationId
    ...
}