Question

我有一个entityA，它包含entityB的EntityCollection。我使用[include]装饰在EntityA的metdata上更新了定义entityB的行，如下所示：

[Include]
public EntityCollection<daily> daily { get; set; }

在我的domainservice类中，我有一个函数来检索entityA，如下所示：

var summary =
(from S in ObjectContext.summery.Include("daily")
                 where S.daily_number == daily_number
                 && S.month_number == month_number
                 && S.period_id == period_id
                 select S).FirstOrDefault();
            return summary;

从客户端我总是得到entityB的零。我在这里错过了什么!!

祝你好运

Answer 1

您需要使用AssociationAttribute定义summery和daily之间的关联。

[Include]
[Association("SomeUniqueName", "summery_id", "parent_summery_id", IsForeignKey = false)]
public EntityCollection<daily> daily { get; set; }

我对你的课程进行了以下假设

public class summery
{
...
    public int? summery_id { get; set; }
...
}

public class daily
{
...
    // Foreign key to the parent summery
    public int parent_summery_id { get; set; }
...
}

修改

在回应Waleed的评论时，复合外键关联看起来像

[Association("SomeUniqueName", "summery_field1, summary_field2, summary_field3", "parent_summary_filed1, parent_summary_filed2, parent_summary_filed3", IsForeignKey = false)]

从另一个实体中获取EntityCollection

1 个答案: