此 SqlParameterCollection 的索引 N 无效，Count=N”服务器错误

Question

我在这里 read many posts 关于标题中提到的异常。通常，此异常意味着我在某处将字段映射到一个实体。我花了很多时间查看我的映射，但仍然找不到问题所在。你能帮我理解这里做错了什么吗：

public class CustomerSegment : ModelEntity, IEntityDescriptor
{
    public const string Standart = "Standard";

    public virtual string Name { get; set; }
    public virtual NetworkNHMapped Network { get; set; }

    public virtual string GetDescriptor()
    {
        return Name;
    }
}

public class CustomerSegmentMap : ClassMap<CustomerSegment>
{
    public CustomerSegmentMap()
    {
        Table("NetworkProperty");
        Id(x => x.Id).Column("NetworkPropertyId");
        Map(x => x.Name).Column("PropertyName");
        References(x => x.Network).Column("NetworkId");
    }
}

}

当我尝试从数据库中获取所有 CustomerSegment 实体时发生异常。

其他实体的代码：

public class NetworkNHMapped : ModelEntity
{
    [StringLength(50)]
    public virtual string Name { get; set; }
    public virtual int NetworkOwnerId { get; set; }
    public virtual int NetworkTypeId { get; set; }

    public virtual RepairShop.NetworkType NetworkType { get { return (RepairShop.NetworkType)NetworkTypeId; } }
}

public class NetworkNewMap : ClassMap<NetworkNHMapped>
{
    public NetworkNewMap()
    {
        Table("Network");
        Id(x => x.Id, "NetworkId");
        Map(x => x.Name, "NetworkName");
        Map(x => x.NetworkOwnerId, "NetworkOwnerId");
        Map(x => x.NetworkTypeId, "NetworkType");
    }
}

基础模型实体：

public virtual int Id { get; set; }

    public override int GetHashCode()
    {
        if (!IsPersisted())
        {
            return base.GetHashCode();
        }

        unchecked
        {
            int result = GetObjectRealType(this).GetHashCode();
            result = 42 * result + Id.GetHashCode();
            return result;
        }
    }

    public override bool Equals(object other)
    {
        if (ReferenceEquals(this, other))
        {
            return true;
        }

        if ((other == null) || !(other is ModelEntity))
        {
            return false;
        }

        var thisType = GetObjectRealType(this);
        var otherType = GetObjectRealType(other);

        if (thisType != otherType)
            return false;

        if (Id.Equals(default(long)) && (other as ModelEntity).Id.Equals(default(long)))
        {
            return base.Equals(other);
        }
        return Id == (other as ModelEntity).Id;
    }

    public static bool operator ==(ModelEntity entity1, ModelEntity entity2)
    {
        var obj1 = (object)entity1;
        if (obj1 == null && ((object)entity2) == null)
            return true;

        return obj1 != null && entity1.Equals(entity2);
    }

    public static bool operator !=(ModelEntity entity1, ModelEntity entity2)
    {
        return !(entity1 == entity2);
    }

    public virtual bool IsPersisted()
    {
        return Id > 0;
    }

    protected static Type GetObjectRealType(object obj)
    {
        return (obj is INHibernateProxy) ? NHibernateUtil.GetClass(obj) : obj.GetType();
    }

}

Answer 1

我要做的第一件事是查看正在生成的 XML 文件，这会显示您是否对同一属性有重复的映射。

如果您使用的是 NH 和 ModelMapper，那么只需致电 WriteAllXmlMapping 例如：-

var mapper = new ModelMapper();
mapper.AddMappings(typeof(CmsMeta).Assembly.GetTypes());

//This will write all the XML into the bin/mappings folder
mapper.CompileMappingForEachExplicitlyAddedEntity().WriteAllXmlMapping();

如果您使用的是 Fluent NHibernate，请查看此blog post 以导出您的 XML。

在您生成 XML 之后，我敢打赌，您会发现重复的映射！否则请参阅此blog post，如果您将外键以及使用many-to-one ... 暴露给映射文件中的相关实体，则有可能。如果是这种情况，请将 insert="false" 和 update="false" 添加到外键属性并再次运行。

无论哪种方式生成 XML 并查看，如果您看不到它，请将相关的 XML 文件发布到您的问题中，我们会查看。