Question

使用GORM / Grails 2.3.7 / Hibernate 3.6，无脚手架。

我的理解Hibernate使用延迟加载，为什么我的映射急切地获取？

TEAM  ---has many-->  MAILBOX

class Team {
   Long id
   Long version

   static hasMany = [mailboxes:Mailbox]
   static mapping = {
      id       sqlType:'number', generator: 'native' 
      version  sqlType:'number'
   }

class Mailbox {
   Long id
   Team team

   static belongsTo = [team:Team]
   static mapping = {
      id       sqlType:'number', generator: 'native' 
   }

问题

调用Team.get(id)时，返回的对象包含完全实例化的所有邮箱。除非调用team.getMailboxes()，否则我期望邮箱为空，映射是否错误？

试过

删除了邮箱中的反向引用：

 class Mailbox {
      Long id
      //Team team
      static belongsTo = Team   //before [team:Team]

没有影响，

还从sql输出确认Hibernate正在抢夺邮箱：

Hibernate: select team0_.id as id1_0_, team0_.version as version1_0_, team0_.name as name1_0_ from team team0_ where team0_.id=?
Hibernate: select mailboxes0_.team_mailboxes_id as team1_1_0_, mailboxes0_.mailbox_id as mailbox2_0_ from team_mailbox mailboxes0_ where mailboxes0_.team_mailboxes_id=?
Hibernate: select mailbox0_.id as id0_0_, mailbox0_.version as version0_0_, mailbox0_.name as name0_0_ from mailbox mailbox0_ where mailbox0_.id=?

我想也许这与hibernate缓存有关，但我已经禁用了它：

hibernate {
    cache.use_second_level_cache = false
    cache.use_query_cache = false
    cache.region.factory_class = 'net.sf.ehcache.hibernate.EhCacheRegionFactory'
    singleSession = false
}

Answer 1

您对延迟加载的理解是错误的。如果你定义一个懒惰加载的对象或集合，那并不意味着它们应该返回null。相反，你会得到一个proxy一个collection of proxies的回复，这会导致＆＃34;膨胀＆＃34;只要您显式访问延迟加载对象的属性

GORM一对多映射默认情况下执行急切提取

问题

试过

1 个答案: