使用的DetachedCriteria的子查詢條款

Question

我想「在」子句中使用一個分離標準作爲子查詢，但不知它不工作：

def trades = new DetachedCriteria(Trade).build { 
      projections { property "tradeNbr" } 
} 

def activities = Activiies.withCriteria { 
      'in' "tradeNumber", trades 
} 

這是我遇到的錯誤：

2012-11-07 01:07:09,088 [http-bio-8081-exec-1] TRACE sql.BasicBinder - f228562 - binding parameter [1] as [INTEGER] - grails.gorm.DetachedCriteria@57c4e7b2 



grails.gorm.DetachedCriteria cannot be cast to java.lang.Integer. Stacktrace follows: 
java.lang.ClassCastException: grails.gorm.DetachedCriteria cannot be cast to java.lang.Integer 
      at grails.orm.HibernateCriteriaBuilder.invokeMethod(HibernateCriteriaBuilder.java:1587) 
      at org.grails.datastore.gorm.GormStaticApi.withCriteria(GormStaticApi.groovy:282) 

Answer 1

我相信list只有在這個意義上默認，你可以用它在each構建像

trades.each { 
    println it 
} 

而這是因爲它實現了Iterable。否則，您實際上必須使用trades.list()運行查詢。僅使用trades就是指DetachedCriteria對象。

def activities = Activities.withCriteria { 
    'in'("tradeNumber", trades.list()) 
}