NHibernate 对合并日期的比较约束

Question

这里有一个很好的 Q/A 来作为这个问题的前言： NHibernate COALESCE issue

我需要能够将日期对象与内部联接中的日期值进行比较。这里不熟悉的领域是此 COALESCE 的实施以及日期 LT 约束

这是我当前的 SQL 查询

SELECT DISTINCT Sites.*
FROM Sites
 INNER JOIN Sites_WF_Info
       ON Site_Key = SiteWFInfo_Site_Key
       AND SiteWFInfo_Effective_Date <= @today
       AND @today <= SiteWFInfo_End_Date
 INNER JOIN Profit_Centers
       ON Site_Key = ProfCtr_Site_Key
       AND ProfCtr_Open_Date <= @today
       AND @today < Coalesce(ProfCtr_Close_Date, '6/6/2079')

我想知道的是如何使用常量代替 ExpenseReport.PeriodFrom 属性 ==> 左边。

理想情况下，我想设置left/right

// DateTime effDate is passed in
var left = Projections.Property<DateTime>(effDate);
var right = Projects.SqlFunction("COALESCE",
            NHibernateUtil.DateTime,
            Projections.Constant(DateTime.Parse("6/6/2079").Date, NHibernateUtil.DateTime),
            Projections.Property<ProfitCenter>(pc => pc.CloseDate));

然后，当调用限制时

var restriction = Restrictions.LtProperty(left, right);

这样当我构建 QueryOver<> 时，我可以用这个 restriction 对象替换其中一个 Where 子句

var foo = CurrentSession().QueryOver<Site>(() => sa)
    .Inner.JoinQueryOver<ProfitCenter>(() => pca)
    .Where(restriction)

最终答案

这需要引入一个新的 'flattened' 域 'ResultModel' (SiteWithWindowsTimezoneId) 以便我可以 return 从我的查询中获得更具体的模型并避免延迟加载所有其他内容当前与网站相关联。这种新的查询样式将 16+ sql 种查询方法简化为单个查询。节省下来的时间是值得的。再次感谢你的帮助。我希望这个要点对以后的人有所帮助。

SiteWorkforceInfo swia = null;
SiteWorkforceConfig swcfg = null;
ProfitCenter pca = null;
Site sa = null;
SiteWithWindowsTimezoneId siteResult = null;

var leftProfCloseDate = Projections.Constant(effectiveDate);
var rightProfCloseDate = Projections.SqlFunction("COALESCE", 
    NHibernateUtil.DateTime, 
    Projections.Property<ProfitCenter>(pc => pc.CloseDate),
    Projections.Constant(DateTime.Parse("6/6/2079").Date, NHibernateUtil.DateTime)
);

var profCloseDateRestriction = Restrictions.LtProperty(leftProfCloseDate, rightProfCloseDate);

var activeSites = CurrentSession().QueryOver<SiteWorkforceInfo>(() => swia)
    .Inner.JoinQueryOver<Site>(() => swia.Site, () => sa)
    .Left.JoinQueryOver<SiteWorkforceConfig>(() => sa.SiteWFConfig, () => swcfg)
    .Inner.JoinQueryOver<ProfitCenter>(() => sa.ProfitCenters, () => pca)
    .Where(() => swia.EffectiveDate <= effectiveDate)
    .Where(() => effectiveDate <= swia.EndDate)
    .Where(() => pca.OpenDate <= effectiveDate)
    .Where(profCloseDateRestriction)
    .Where(() => swia.TimeCaptureRule > 0)
    .SelectList(
        list => list
            .Select(() => sa.Key).WithAlias(() => siteResult.Key)
            .Select(() => sa.Id).WithAlias(() => siteResult.Id)
            .Select(() => sa.IdFormatted).WithAlias(() => siteResult.IdFormatted)
            .Select(() => sa.Description).WithAlias(() => siteResult.Description)
            .Select(() => swcfg.WindowsTimezoneId).WithAlias(() => siteResult.WindowsTimezoneId)
                )
    .TransformUsing(Transformers.AliasToBean<SiteWithWindowsTimezoneId>())
    .List<SiteWithWindowsTimezoneId>();

return activeSites;

--- 结果查询 ---

SELECT sa1_.Site_Key as y0_, 
    sa1_.Site_Id as y1_, 
    sa1_.Site_Id_Formatted as y2_, 
    sa1_.Site_Description as y3_, 
    swcfg2_.SiteWFCfg_Windows_Timezone_Id as y4_ 
FROM Sites_WF_Info this_ 
inner join Sites sa1_ 
    on this_.SiteWFInfo_Site_Key=sa1_.Site_Key 
inner join Profit_Centers pca3_ 
    on sa1_.Site_Key=pca3_.ProfCtr_Site_Key 
left outer join Sites_WF_Configuration swcfg2_ 
    on sa1_.Site_Key=swcfg2_.SiteWFCfg_Site_Key 
WHERE this_.SiteWFInfo_Effective_Date <= @p0 
    and @p1 <= this_.SiteWFInfo_End_Date 
    and pca3_.ProfCtr_Open_Date <= @p2 
    and @p3 < coalesce(pca3_.ProfCtr_Close_Date, @p4) 
    and this_.SiteWFInfo_TimeCapRule_Key > @p5

Answer 1

如果我理解正确，我们需要用 effDate 常量投影替换 left （当前属性投影）。那么我们可以这样操作

// instead of this
// var left = Projections.Property<DateTime>(effDate);

// we would use this
// DateTime effDate is passed in
var effDate = DateTime.Today.Date; // C#'s today
var left = Projections.Constant(effDate);

此外，我们应该切换 "COALESCE" 的 （更改顺序），因为属性应该先进行：Coalesce(ProfCtr_Close_Date, '6/6/2079')

var right = Projects.SqlFunction("COALESCE",
    NHibernateUtil.DateTime,

    // As DOC of COALESCE says:
    // "Evaluates the arguments in order and returns the current value of 
    //  the first expression that initially does not evaluate to NULL."

    Projections.Property<ProfitCenter>(pc => pc.CloseDate), 
    Projections.Constant(DateTime.Parse("6/6/2079").DateNHibernateUtil.DateTime)
    );

最后，我们应该为连接的列使用相同的别名。让我们稍微调整一下主查询：

var foo = CurrentSession().QueryOver<Site>(() => sa)
    .Inner.JoinQueryOver<ProfitCenter>(() =>  sa.ProfitCenter, () => pca)
    .Where(restriction)

右边也应该使用pca

var right = Projects.SqlFunction("COALESCE",
    NHibernateUtil.DateTime,
    // be sure that column goes to correct table
    // ==> use the same alias
    Projections.Property(() => pca.CloseDate), 
    Projections.Constant(DateTime.Parse("6/6/2079").DateNHibernateUtil.DateTime)
    );

NHibernate 对合并日期的比较约束

NHibernate comparison constraint to a coalesced date

c#

nhibernate

nhibernate-criteria

queryover