Question

我有一个表团队，我有一个表位置。每个团队可以有多个位置，每个位置可以有多个团队，因此这是一个多对多的关系。

在数据库中创建此方案时，将有3个表，Team，Location和TeamLocation来保存多个到多个链接。

我使用以下内容在nhibernate中映射了这个... Team.hbm.xml

<class name="App.Data.Entities.Team,App.Data.Entities" table="`Team`" lazy="true">
   <id name="Teamid" column="`TeamID`" type="Guid">
      <generator class="assigned" />
    </id>
    <property type="string" not-null="true" length="250" name="TeamName" column="`TeamName`" />
    <bag name="TeamLocations" inverse="false" table="`TeamLocations`" lazy="true" cascade="all">
      <key column="`TeamID`" />
      <many-to-many class="App.Data.Entities.Location,App.Data.Entities">
        <column name="`LocationID`" />
      </many-to-many>
    </bag>
    </class>

和Location.hbm.xml

<class name="App.Data.Entities.Location,App.Data.Entities" table="`Location`" lazy="true">
    <id name="Locationid" column="`LocationID`" type="int">
      <generator class="native" />
    </id>
    <property type="string" not-null="true" length="250" name="LocationName" column="`LocationName`" />
    <property type="string" length="1000" name="Address" column="`Address`" />
    <bag name="Teams" inverse="false" table="`TeamLocations`" lazy="true" cascade="all">
      <key column="`LocationID`" />
      <many-to-many class="App.Data.Entities.Team,App.Data.Entities">
        <column name="`TeamID`" />
      </many-to-many>
    </bag>
  </class>

现在我正在尝试使用条件API检索所有基于特定位置的团队，我无法...

等效的sql ...

SELECT     Team.TeamName, Location.LocationName
FROM         Team INNER JOIN
                      TeamLocations ON Team.TeamID = TeamLocations.TeamID INNER JOIN
                      Location ON TeamLocations.LocationID = Location.LocationID
WHERE     (TeamLocations.LocationID = 2)

和asp.net代码

ICriteria criteria = _session.CreateCriteria(typeof(Team)).SetFirstResult(startRowIndex).SetMaxResults(maximumRows);

if (deptID > 0)
{
    Department dept = new Department(deptID);
    criteria.Add(Expression.Eq(Team.PropertyNames.Department, dept)); //for department, which works fine.
}

if (locationIDs.Count > 0)
{
    List<Location> locations = new List<Location>();

    foreach (int locationID in locationIDs)
    {
        Location loc = new Location(locationID);
        locations.Add(loc);
    }

    criteria.CreateCriteria("TeamLocations").Add(Expression.Eq(""TeamLocations"", locations));
}

return criteria.List<Team>();

这引发错误..

could not resolve property: TeamLocations of: App.Data.Entities.Location

我无法弄清楚：（

纠正我.. 谢谢！

Answer 1

您可以像我下面那样添加restriction to an association path using CreateCriteria or CreateAlias。我必须更多地了解您的模型和映射，以了解为什么您可以在Team.PropertyNames.Department上添加限制而不对其进行别名化。

    ICriteria criteria = _session.CreateCriteria(typeof(Team)).SetFirstResult(startRowIndex).SetMaxResults(maximumRows);

if (deptID > 0)
{
    Department dept = new Department(deptID);
    criteria.Add(Expression.Eq(Team.PropertyNames.Department, dept)); //for department, which works fine.
}

if (locationIDs.Count > 0)
{
    // you may need to convert locationIds to an ICollection e.g.
    // var ids = locationIds.ToArray();
    criteria.CreateAlias("TeamLocations", "teamLocations");
    criteria.Add(Restrictions.In("teamLocations.LocationId", locationIds));
}

return criteria.List<Team>();

nhibernate - 通过中间表的标准

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