NHibernate

Question

我需要从同一个 table 加载三个一对多关系到其他三个 table。以下是我的 table:

的 ERD

ProcessActionLog是与ProcessActionEmail、三个一对多关系的table基于 ProcessActionType 列的 ProcessActionInterviewFeedback 和 ProcessActionNotesInfo tables 将包含以下列的名称我对这些 table 的映射：

1) ProcessActionLog Table 映射：

class ProcessActionLogMap : ClassMap<ProcessActionLog>
    {
        public ProcessActionLogMap()
        {
            //Rest of mappings//
            HasMany(x => x.ProcessActionEmail).Cascade.SaveUpdate().Inverse();
            HasMany(x => x.ProcessActionInterviewFeedback).Cascade.SaveUpdate().Inverse();
            HasMany(x => x.ProcesssActionNotesInfo).Cascade.SaveUpdate().Inverse();
        }

2) ProcessActionEmailMapping:

class ProcessActionEmailMap : ClassMap<ProcessActionEmail>
    {
        public ProcessActionEmailMap()
        {
            //rest of mappings//
            References(x => x.ProcessActionLog, "ProcessActionLogId");
        }
    }

3) ProcessActionInterviewFeedback 映射：

class ProcessActionInterviewFeedbackMap : ClassMap<ProcessActionInterviewFeedback>
    {
        public ProcessActionInterviewFeedbackMap()
        {
            //Rest of mappings//
            References(x => x.ProcessActionLog, "ProcessActionLogId");
        }
    }

4) ProcessActionNotesInfo

class ProcessActionNotesInfoMap : ClassMap<ProcessActionNotesInfo>
    {
        public ProcessActionNotesInfoMap()
        {
            //Rest of mappings//
            References(x => x.ProcessActionLog, "ProcessActionLogId");
        }
    }

现在我尝试了以下查询，以便预先加载所有三个关系：

 public IList<ProcessActionLog> FetchUserSpecificProcessActionLogs(int UserId)
        {
            return _session.Query<ProcessActionLog>()
                            .Where(x => x.MasterUser.Id == UserId)
                            .Fetch(x => x.ProcessActionEmail)
                            .Fetch(x => x.ProcessActionInterviewFeedback)
                            .Fetch(x => x.ProcesssActionNotesInfo)
                            .ToFuture().ToList<ProcessActionLog>();
        }

但这给了我以下错误：

Cannot simultaneously fetch multiple bags.

请帮助我解决此问题或建议我可以使用 ProcessActionLog Table 的 processActionType 列急切加载实体的任何其他方法。谢谢。

Answer 1

最后，通过在映射中使用 ISet 而不是 IList 解决了这个问题，现在我的代码如下：

ProcessActionLog 实体

    public class ProcessActionLog
    {
        /// <summary>
        /// Process Action Emails 
        /// </summary>
        private ISet<ProcessActionEmail> _ProcessActionEmail { get; set; }
        /// <summary>
        /// Process Action Interview Feedbacks
        /// </summary>
        private ISet<ProcessActionInterviewFeedback> _ProcessActionInterviewFeedback { get; set; }
        /// <summary>
        /// Process action notes info
        /// </summary>
        private ISet<ProcessActionNotesInfo> _ProcessActionNotesInfo { get; set; }
        /// <summary>
        /// Is process action email
        /// </summary>
        public virtual bool IsProcessActionEmail
        {
            get { return ProcessActionType == ProcessActionType.ProcessActionEmail; }
        }
        /// <summary>
        /// Is process action interview feedback
        /// </summary>
        public virtual bool IsProcessActionInterviewFeedback
        {
            get { return ProcessActionType == ProcessActionType.ProcessActionInterviewFeedback; }
        }
        /// <summary>
        /// Is process action notes info
        /// </summary>
        public virtual bool IsProcessActionNotesInfo
        {
            get { return ProcessActionType == ProcessActionType.ProcessActionNotesInfo; }
        }
        /// <summary>
        /// Process Action Log setter and getter
        /// </summary>
        public virtual ISet<ProcessActionEmail> ProcessActionEmail
        {
            get { return (IsProcessActionEmail ? _ProcessActionEmail : null); }
            set { _ProcessActionEmail = value; }
        }
        /// <summary>
        /// Process Action Interview Feedback setter and getter
        /// </summary>
        public virtual ISet<ProcessActionInterviewFeedback> ProcessActionInterviewFeedback
        {
            get { return (IsProcessActionInterviewFeedback ? _ProcessActionInterviewFeedback : null); }
            set { _ProcessActionInterviewFeedback = value; }
        }
        /// <summary>
        /// Process Action Notes info setter and getter
        /// </summary>
        public virtual ISet<ProcessActionNotesInfo> ProcessActionNotesInfo
        {
            get { return (IsProcessActionNotesInfo ? _ProcessActionNotesInfo : null); }
            set { _ProcessActionNotesInfo = value; }
        }
    }

ProcessActionEmail 实体

public class ProcessActionEmail
{
    //Rest of the attributes

    /// <summary>
    /// Process Action log of this particular email
    /// </summary>
    public virtual ProcessActionLog ProcessActionLog { get; set; }

ProcessActionInterviewFeedback 实体

public class ProcessActionInterviewFeedback 
{
    /// <summary>
    /// Process Action Log
    /// </summary>
    public virtual ProcessActionLog ProcessActionLog { get; set; }
}

ProcessActionLog 映射

 class ProcessActionLogMap : ClassMap<ProcessActionLog>
    {
        public ProcessActionLogMap()
        {
            Id(x => x.Id);
            Map(x => x.LogName).Length(100).Not.Nullable();
            Map(x => x.ProcessActionType).CustomType<Int32>().Not.Nullable();
            Map(x => x.CreatedAt).CustomType<DateTime>().Not.Nullable();
            References(x => x.MasterUser).Column("UserId");
            References(x => x.Process).Column("ProcessId");
            References(x => x.SystemUser).Column("CreatedBy");
            References(x => x.Task).Column("TaskId").Nullable();
            HasMany(x => x.ProcessActionEmail).Cascade.SaveUpdate().Inverse();
            HasMany(x => x.ProcessActionInterviewFeedback).Cascade.SaveUpdate().Inverse();
            HasMany(x => x.ProcessActionNotesInfo).Cascade.SaveUpdate().Inverse();
        }
    }

并且查询与问题中的相同。

NHibernate - 基于类型列的渴望加载一对多关系

NHibernate - Eager load one-to-many relationship on the basis of type column

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