NHibernate-查询错误的列

Question

我遇到了NHibernate的间歇性问题，该问题会为实体生成查询，但是用来自完全不同（且不相关）的实体的列替换了其中的一列。

它只能替换单个列，通常可以通过重新启动应用程序来解决（尽管有时需要进行几次尝试）。

• ASP.NET应用程序（.NET 4.0）
• 在Application_Start期间创建的SessionFactory
• NHibernate 3.3.1-通过代码映射完成所有映射/配置
• 使用Nhibernate条件

任何输入对此将不胜感激！

实体

public class LiquiditySourceItem : RunDataEntity, IEntity<int>
    {
        public virtual int Id { get; protected internal set; }
        public virtual int IdentID { get; protected internal set; }
        public virtual string Portfolio { get; protected internal set; }
        public virtual string ProfitCentre { get; protected internal set; }
        public virtual DateTime? MaturityDate { get; protected internal set; }
        public virtual string Curr1 { get; protected internal set; }
        public virtual string Curr2 { get; protected internal set; }
        public virtual decimal Reval { get; protected internal set; }
        public virtual string ContractType { get; protected internal set; }
        public virtual string ContractType2 { get; protected internal set; }
        public virtual string ContractCode { get; protected internal set; }
        public virtual decimal AmountSignedTradeUnit { get; protected internal set; }
        public virtual decimal Amount2Signed { get; protected internal set; }
        public virtual decimal SpotDelta { get; protected internal set; }
        public virtual string TradeRevalCurr { get; protected internal set; }
    }

实体映射

public LiquiditySourceItemMap()
{
    Id(x => x.Id, map => map.Column("RowId"));
    Property(x => x.IdentID, map => map.Column("IdentID"));
    Property(x => x.Portfolio, map => map.Column("Portfolio"));
    Property(x => x.ProfitCentre, map => map.Column("ProfitCentre"));
    Property(x => x.MaturityDate, map => map.Column("Con_Expiry"));
    Property(x => x.BuySell, map => map.Column("BS"));
    Property(x => x.Curr1, map => map.Column("Curr1"));
    Property(x => x.Curr2, map => map.Column("Curr2"));
    Property(x => x.Reval, map => map.Column("Reval"));
    Property(x => x.ContractType, map => map.Column("ContractType"));
    Property(x => x.ContractType2, map => map.Column("ContractType2"));
    Property(x => x.ContractCode, map => map.Column("ContractCode"));
    Property(x => x.AmountSignedTradeUnit, map => map.Column("AmountSignedTradeUnit"));
    Property(x => x.Amount2Signed, map => map.Column("Amount2Signed"));
    Property(x => x.ValSpot, map => map.Column("Val_Spot"));
    Property(x => x.SpotDelta, map => map.Column("SpotDelta"));
    Property(x => x.TradeRevalCurr, map => map.Column("Traderevalcurr"));
    Property(x => x.SourceReport, map => map.Column("SourceReport"));
    ManyToOne(x => x.RunContext, map => map.Column("RunContextID"));
    Table("Staging.vw_Liquidity");
}

报告实体

public class BusinessBreakdownStandardPosition : ReportRunDataEntity, IEntity<long>
    {
        public virtual long Id { get; set; }
        public virtual decimal FinalNettingAmountUSD { get; set; }
        public virtual decimal InitialChargeAmountUSD { get; set; }
        public virtual BusinessBreakdownInitialPrr InitialPrr { get; set; }
        public virtual IEnumerable<FinalInstrumentPosition> FinalInstrumentPositions { get; set; }
        public virtual decimal CreditEventPaymentUSD { get; set; }
        public virtual decimal ValuationChangeIncreaseUSD { get; set; }
        public virtual decimal ValuationChangeDecreaseUSD { get; set; }
        public virtual string ReportKey { get; set; }
        public virtual decimal USDCharge { get; set; }
        public virtual decimal USDChargeICG { get; set; }
        public virtual string InstrumentType { get; set; } 
}

报告实体映射

public class BusinessBreakdownStandardPositionMap : ClassMapping<BusinessBreakdownStandardPosition>
    {
        public BusinessBreakdownStandardPositionMap()
        {
            Id(x => x.Id,
               m =>
                   {
                       m.Column("BusinessBreakdownStandardPositionID");
                       m.Generator(Generators.HighLow,
                                   g =>
                                   g.Params(
                                       new
                                           {
                                               table = "dbo.HiValue",
                                               max_lo = 10000,
                                               Where = string.Format("EntityName = 'BusinessBreakdownStandardPosition'")
                                           }));
                   });
            Property(x => x.FinalNettingAmountUSD, map => map.Column("FinalNettingAmountUSD"));
            Property(x => x.InitialChargeAmountUSD, map => map.Column("InitialAmountUSD"));
            Property(x => x.CreditEventPaymentUSD);
            Property(x => x.ValuationChangeDecreaseUSD);
            Property(x => x.ValuationChangeIncreaseUSD);
            Property(x => x.USDCharge);
            Property(x => x.USDChargeICG);
            Property(x=>x.InstrumentType);
            ManyToOne(p => p.RunContext, map => map.Column("ReportRunContextID"));
            ManyToOne(p => p.InitialPrr, m =>
                {
                    m.Column("InitialPrrID");
                    m.Cascade(Cascade.All);
                });
            Property(x => x.ReportKey);
            Bag(x => x.FinalInstrumentPositions, collectionMapping =>
                {
                    collectionMapping.Table("Reporting.BusinessBreakdownFinalInstrumentPositionStandardPositionMap");
                    collectionMapping.Cascade(Cascade.All);
                    collectionMapping.Key(k => k.Column("StandardPositionID"));
                }, mapping => mapping.ManyToMany(y => y.Column("FinalInstrumentPositionID")));
            Table("Reporting.BusinessBreakdownStandardPosition");
        }
    }

NHibernate生成的SQL查询

SELECT
    this_.RowId AS RowId47_0_,
    this_.IdentID AS IdentID47_0_,
    this_.Portfolio AS Portfolio47_0_,
    this_.ProfitCentre AS ProfitCe4_47_0_,
    this_.Con_Expiry AS Con5_47_0_,
    this_.BS AS BS47_0_,
    this_.Curr1 AS Curr7_47_0_,
    this_.Curr2 AS Curr8_47_0_,
    this_.Reval AS Reval47_0_,
    this_.ContractType AS Contrac10_47_0_,
    this_.ContractType2 AS Contrac11_47_0_,
    this_.ContractCode AS Contrac12_47_0_,
    this_.AmountSignedTradeUnit AS AmountS13_47_0_,
    this_.Amount2Signed AS Amount14_47_0_,
    this_.Val_Spot AS Val15_47_0_,
    this_.SpotDelta AS SpotDelta47_0_,
    this_.InitialAmountUSD AS Initial17_47_0_,
    this_.RunContextID AS RunCont18_47_0_,
    this_.SourceReport AS Sou19_47_0_
FROM Staging.vw_Liquidity this_

例外

System.Data.SqlClient.SqlException (0x80131904): Invalid column name 'InitialAmountUSD'.

如您所见，nhibernate已将LiquiditySourceItem列’Traderevalcurr’替换为’InitialAmountUSD’，该列属于BusinessBreakdownStandardPosition实体。这些实体没有任何关系。否则，SQL完全符合您的期望（包括列顺序）。

观察结果

• 错误的列始终是其他映射实体中的有效列
• 错误的列将替换现有的列
• 有时在其他实体之间也会发生此问题。同样，这些之间没有任何关系

有什么想法吗？

Answer 1

我在NHibernate用户Google网上论坛上问了同样的问题，有人认为他们已经找到了根本原因（并且还提出了解决方案）：

https://groups.google.com/forum/#!topic/nhusers/BZoBoyWQEvs

问题代码在PropertyPath.Equals（PropertyPath）中，该属性试图仅通过使用哈希码来确定相等性。这对于较小的代码库来说效果很好，因为默认的Object.GetHashCode（）返回一个顺序的对象索引。但是，在垃圾回收之后，这些索引会在删除最终对象并创建新对象时重新使用…这导致多个对象获得相同的哈希码…一旦启动垃圾回收，属性路径就有机会共享相同的哈希码，这意味着它们最终将为冲突的属性混合其定制器，从而导致错误的列名…

如果要解决此错误，可以修补NH源代码：

如果您拥有自己的NH源副本，则可以通过将NHibernate / Mapping / ByCode /
PropertyPath.cs第66行从以下位置更改来修复该错误：

return hashCode == other.GetHashCode();

到：

return hashCode == other.GetHashCode() && ToString() == other.ToString();

请查看Google网上论坛以获取问题的完整详细信息。