实体：

public class BasePriceRule : BaseEntity
{
    public virtual string Name { get; set; }

    public virtual string RuleString { get; set; }

    public virtual TypePriceRule Type { get; }

    public virtual DateTime Date { get; set; } = DateTime.Now;
}

public class ProductGroupRule : BasePriceRule
{
    public virtual ProductGroup ProductGroup { get; set; }

    public override TypePriceRule Type => TypePriceRule.ProductGroup;
}

public class ProductGroup : BaseEntity
{        
    public virtual string Code { get; set; }

    public virtual string Name { get; set; }

    public virtual string Description { get; set; }

    public virtual UoM UoM { get; set; }

    public virtual CustomProductType Type { get; set; }
}

映射：

public class BasePriceRuleMap : ClassMap<BasePriceRule>
{
    public BasePriceRuleMap()
    {
        Table("PriceRule");
        Id(x => x.Id);

        Map(x => x.Name);
        Map(x => x.RuleString).Length(4096);

        DiscriminateSubClassesOnColumn("Type");
        Map(x => x.Type).CustomType<TypePriceRule>().ReadOnly().Access.None().Not.Nullable();

        Map(x => x.Date).Not.Nullable().Default("CURRENT_TIMESTAMP");
    }
}

public ProductGroupRuleMap()
{
    KeyColumn("Id");

    References(x => x.ProductGroup).Fetch.Join()/*.Not.Update()*/;
    DiscriminatorValue((int)TypePriceRule.ProductGroup);
}

public ProductGroupMap()
{
    Id(x => x.Id);

    Map(x => x.Code).Unique();
    Map(x => x.Name);
    Map(x => x.Description);
    Map(x => x.Type).CustomType<int>();

    References(x => x.UoM);
}

所以当我运行这个最简单的查询时：

_session.QueryOver<ProductGroupRule>();

或者这个：

_session.QueryOver<ProductGroupRule>().Fetch(x => x.ProductGroup).Eager.List();

我收到这个生成的sql：

2016-11-18 17:17:39.3103 NHibernate.SQL  SELECT this_.Id as Id62_1_, this_.Name as Name62_1_, this_.RuleString as RuleString62_1_, this_.Type as Type62_1_, this_.ProductGroup_id as ProductG6_62_1_, productgro2_.Id as Id66_0_, productgro2_.Code as Code66_0_, productgro2_.Name as Name66_0_, productgro2_.Description as Descript4_66_0_, productgro2_.Type as Type66_0_, productgro2_.UoM_id as UoM6_66_0_ FROM PriceRule this_ left outer join [ProductGroup] productgro2_ on this_.ProductGroup_id=productgro2_.Id WHERE this_.Type='2'
2016-11-18 17:17:39.4474 NHibernate.SQL  Batch commands:
command 0:UPDATE [ProductGroup] SET Code = @p0, Name = @p1, Description = @p2, Type = @p3, UoM_id = @p4 WHERE Id = @p5;
command 1:UPDATE [ProductGroup] SET Code = @p0, Name = @p1, Description = @p2, Type = @p3, UoM_id = @p4 WHERE Id = @p5;
--Numbers of commands are equal to the amount of records in PriceRule table

我试过了：

启用/禁用延迟加载
将Cascade更改为None，Evict
为ProductGroup参考设置Not.Update（）
使用Future＆lt;＆gt;

但仍然无法摆脱它们。

有人可以解释为什么会出现这些更新命令吗？

Answer 1

在ProductGroup定义中，有一个属性，不能 null - CustomProductType Type

public class ProductGroup : BaseEntity
{        
    public virtual string Code { get; set; }
    public virtual string Name { get; set; }
    public virtual string Description { get; set; }
    public virtual UoM UoM { get; set; }
    // this cannot be null
    public virtual CustomProductType Type { get; set; }
}

C＃会将其设置为默认值（通常是第一个enum）

但似乎在DB中，相关列包含null。对于NHibernate，它是一个符号：1）loaded是NULL，但是在检查对象时 - 2）它有一个赋值。

所以，对象很脏，因为Flush模式默认是AUTO ...它试图保持DB和C＃实例同步

只需更改映射

即可

    public virtual CustomProductType? Type { get; set; }

Answer 2

我的猜测是发生了自动冲洗，NH认为那些ProductGroup对象由于某种原因是脏的。恕我直言，最好的行动方案是enable logging通过log4net获取一些详细的诊断信息。 NH的伐木非常好。你应该能够通过它来了解这一点。

在Nhibernate中选择后出现意外的批量更新命令

实体：

映射：

2 个答案: