NHibernate Criteria API 错误，创建别名和投影集合

Question

我的任务是使用 NHibernate Criteria API 生成成员数据列表。我需要根据用户界面中的复选框合并分页和过滤。使这一点变得更复杂的是，我不仅从一个实体获取数据，而且该实体与其他实体具有 HasMany 关系。

我目前有一个错误：

Error executing multi Criteria: 
[SELECT DISTINCT TOP 1000 this_MemberID as y0_ 
 FROM _Members
 Left Outer Join _SubMemberTerms ON _SubMemberTerms.MemberID = this_.MemberID
 Left Outer Join _MemberTerms ON _MemberTerms.MemberID = this_.MemberID
 Left Outer Join _ScriptOption ON _ScriptOption.ID = _MemberTerms.ScriptOpID
 WHERE _MagazineID = 100
 AND 
    (_ScriptOption.MagID IN (1234,5678,9101,.....) 
        OR _ScriptOption.MemberID IS NULL
        OR _ScriptOption.Active = 0)
 AND
    (_SubMemberTerms._ScriptOpID IN (1234,5678,9101,.....)
        OR _SubMemberTerms.ID IS NULL);]

内部异常是：值“5554302”不是类型 \"MyBusiness.MemberInfo\" 且不能在此通用中使用 收藏。参数名称：值。

现在我只是查看会员的 ID，因为我评论了我的投影列表中的所有其他投影。否则错误会指出“The Value \”System.object[]\”...

我的条件代码：

var filteredList = CurrentSession.CreateCriteria<MemberInfo>("this_")
                   .SetProjection(Projections.Distinct(Projections.ProjectionList()
                   .Add(Projections.Alias(Projections.Property("ManagedMemberID"), "MemberID"))))
                   .Add(Restrictions.Eq("_MagazineID", (int)magID))
                   .CreateAlias("MemTermsList", "_MemberTerms", NHibernate.SqlCommand.JoinType.LeftOuterJoin)
                   .CreateAlias("_MemberTerms.ScriptOpInfo", "_ScriptOption", NHibernate.SqlCommand.JoinType.LeftOuterJoin)
                   .CreateAlias("SubTermsList", "_SubMemberTerms", NHibernate.SqlCommand.JoinType.LeftOuterJoin)
                   .SetFirstResult(startposition)
                   .SetMaxResults(1000);

我还有一个 Criteria 用于获取总查询的计数，而不仅仅是返回的 1k 与我为 filteredList 所做的 Criteria 相同

//code for how I'm adding in the MagID's and ScriptOpId's
Disjunction magDisjunction = new Disjunction();
Disjunction subTermsDijunction = new Disjunction();
if(TheCheckBoxThatAppliesIsChecked)
{
    magDisjunction.Add(Restrictions.In("_ScriptOption.MagID", (List<int>)selectedMags))
                  .Add(Restrictions.IsNull("_MemberTerms.MemberID"))
                  .Add(Restrictions.Eq("_MemberTerms.Active", false));

    filteredList.Add(magDisjunction);
}
if(TheOtherCheckBoxThatAppliesIsChecked)
{
    subTermsDisjunction.Add(Restrictions.In("_SubMemberTerms.SciptOpID", (List<int>)selectedScriptOp))
                  .Add(Restrictions.IsNull("_SubMemberTerms.SubMemberTermsID"));

    filteredList.Add(subTermsDisjunction);
}

var finishedList = filteredList.Future<MemberInfo>().ToList<MemberInfo>();
var count = listCount.FutureValue<int>().Value;

： 我的投影中出现拼写错误。别名，将“MemberID”切换为“ManagedMemberID”。

Answer 1

查询 filteredlist has

.SetProjection(Projections.Distinct(Projections.ProjectionList().Add(Projections.Alias(Projections.Property("MemberID"), "MemberID"))))

which 与 which 相同

.SetProjection(Projections.Distinct(Projections.Property("MemberID")))

，这意味着查询 filteredlist 返回 MemberID 但

var finishedList = filteredList.Future<MemberInfo>().ToList<MemberInfo>();

声明 filteredList 返回 MemberInfo这会导致错误

注意：

Future() 只是一个noop，因为您立即调用ToList()。将其更改为

var finishedList = filteredList.Future<int>();
var count = listCount.FutureValue<int>();

获取查询批处理

更新：

我将摆脱投影并使用

int count = CriteriaUtil.Clone(query).SetProjection(Projections.RowCount()).FutureValue<int>();
var results = query.Future<MemberInfo>();


View.MemberCount = count.Value;  // executes both sql together here
foreach (MemberInfo result in results)
{
    // do something with the result
}