休眠和“不在"；在聚合子查询中 [英] nhibernate and "NOT IN" in a aggregate subquery

问题描述

我有一个实体 Reminder，其中包含 ReminderSchedule 的集合.这是我的映射:

I've got an entity Reminder which contains a collection of ReminderSchedule. This is my mapping:

<class xmlns="urn:nhibernate-mapping-2.2" mutable="true" name="Reminder" table="Reminders">
    <id name="Code" type="System.Guid">
        <column name="ReminderCode" />
        <generator class="guid.comb" />
    </id>
    ...
    <set access="field.pascalcase-underscore" cascade="all-delete-orphan" inverse="true" lazy="false" name="Schedules" mutable="true">
      <key foreign-key="FK_Schedules_Reminders">
        <column name="ReminderCode" />
      </key>
      <one-to-many class="ReminderSchedule" />
    </set>
</class>

这是实体ReminderSchedule的映射:

  <class xmlns="urn:nhibernate-mapping-2.2" mutable="true" name="ReminderSchedule" table="ReminderSchedules">
    <id name="Code" type="System.Guid">
      <column name="ReminderScheduleCode" />
      <generator class="guid.comb" />
    </id>
    <property name="NextSchedule" type="System.DateTime">
      <column name="NextSchedule" index="ReminderScheduleK01" not-null="true" />
    </property>
    <many-to-one class="Reminder" foreign-key="FK_ReminderScheduleToReminder" name="Reminder">
      <column name="ReminderCode" index="ReminderScheduleK02" not-null="true" />
    </many-to-one>
  </class>

ReminderSchedules 表包含与提醒关联的每个新计划的记录.我可以关闭一个时间表 (Closed = 1) 并重新安排一个新的时间表.
在这种情况下，我将有一个 Closed = 0 的新记录，并且 NextSchedule 字段将包含下一个计划的日期/时间.

ReminderSchedules table contains a record for each new scedule associated with a reminder. I can close a schedule (Closed = 1) and reschedule a new one.
In this situation I would have a new records with Closed = 0 and I the field NextSchedule would contain the date/time of the next schedule.

我已经在使用 CreateCriteria 来过滤提醒，而且效果非常好.现在我想获取没有打开任何 ReminderSchedule 的提醒.

I am already using CreateCriteria to filter the reminders and it works pretty very well. Now I would like to fetch the reminders which do not have any ReminderSchedule open.

我已经想出了如何通过查询来做到这一点:

I've figured out how to do it with a query:

SELECT * FROM Reminders
WHERE ReminderCode 
    NOT IN (
        SELECT LastReschedule.ReminderCode FROM (
        SELECT ReminderCode, MAX(NextSchedule) MaxSchedule
        FROM ReminderSchedules
        WHERE Closed = 1 
        GROUP BY ReminderCode) LastReschedule
        )
ORDER BY Reminders.ReminderCode

但我不知道如何将其转换为适用于 nhibernate 的标准.

but I don't know how to translate it in a criteria valid for nhibernate.

有没有人可以帮助我?将不胜感激.

Is there anybody out there who can help me? It would be really appreciated.

推荐答案

由于我无法使用 2 个子查询(嵌套)，我尝试只使用一个子查询来简化.
我已经为关闭的时间表获取了提醒的 ID (Schedules.Reminder.Code).对我来说幸运的是，如果前一个没有关闭，我就不应该有另一个时间表.如果发生了，太糟糕了，我将无法管理它.

Since I haven't been able to use 2 subqueries (nested) I've tried to simplify using just one subquery.
I've fetched the id of the reminder (Schedules.Reminder.Code) for the schedules closed. Luckily for me I shouldn't have another schedule if the previous one hasn't been closed. If it happens, too bad, I won't be able to manage it.

这是我能做的最好的:

ICriteria FiltersCriteria = Session.CreateCriteria<Domain.Reminder>("Reminders");

DetachedCriteria dCriteria = DetachedCriteria.For<Domain.ReminderSchedule>("Schedules")
    .SetProjection(Projections.ProjectionList()
    .Add(Projections.GroupProperty("Schedules.Reminder.Code")))
    // .Add(Projections.Max("Schedules.NextSchedule").As("MaxSchedule")))
    .Add(Restrictions.Eq("Schedules.Closed", true));

FiltersCriteria.Add(Subqueries.PropertyIn("Reminders.Code", dCriteria));  

我猜这个示例代码是不言自明的.
我为子查询使用了 DetachedCriteria，并将它用作我的 Criteria 的参数.

I guess this sample code is self explanatory.
I've used a DetachedCriteria for the subquery and I use it as a parameter for my Criteria.

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