如何使用Fluent NHibernate映射CompositeId的引用

Question

我有三个类Product ， Stock ， StockId 。 Stock具有Token和InternalCode的复合ID，这两个属性封装在新的类StockID 。

我的课程定义是：

public class Producto
{
    public virtual long Id { get; set;
    public virtual Stock Stock { get; set; }

    ... Some other (not so important ) properties ...

    public Producto()
    {
        ...
    }
}

public class Stock
{
    public virtual StockID ID { get; set; }
    public virtual Producto ProductoStock { get; set; }
    ... other properties ...
}

public class StockID
{
    public virtual string Token { get; set; }
    public virtual long CodigoInterno { get; set; }

    public override int GetHashCode()
    {
        int hash = GetType().GetHashCode();
        hash = (hash * 31) ^ CodigoInterno.GetHashCode();
        hash = (hash * 31) ^ Token.GetHashCode();

        return hash;
    }

    public override bool Equals(object obj)
    {
        var other = obj as StockID;

        if (ReferenceEquals(null, other)) return false;
        if (ReferenceEquals(this, other)) return true;

        return this.CodigoInterno == other.CodigoInterno &&
               this.Token == other.Token;
    }
}

这些是地图：

public class ProductoMap : ClassMap<Producto>
{
    public ProductoMap()
    {
        Id(x => x.Id);
        // ... Other Maps and References

        References<Stock>( p => p.Stock);
    }
}

public class StockMap : ClassMap<Stock>
{
    public StockMap()
    {
        CompositeId( stock => stock.ID)
            .KeyProperty(x => x.CodigoInterno)
            .KeyProperty(x => x.Token);

        // ... Other Maps and References
        References(x => x.ProductoStock);
    }
}

这是我得到的例外...

外键（FKD33BD86ADE26BE17：Producto [Stock_id]））的列数必须与引用的主键（股票[CodigoInterno，令牌]）相同

我怎样才能解决这个问题？

Answer 1

您必须将与类别Producto和类别Stock相匹配的属性映射。 它看起来应该像这样：

public class StockMap : ClassMap<Stock>
{
    public StockMap()
    {
        CompositeId( stock => stock.ID)
            .KeyProperty(x => x.CodigoInterno)
            .KeyProperty(x => x.Token);
        // ... Other Maps and References
        //This is ok since you have (i believe) a column in
        //in your table that stores the id from Producto
        References(x => x.ProductoStock).Column("idProducto");
        //Maybe you have to put the name of the column with
        //the id of Producto in your table Stock because
        //you could use it later.

    }
}

和ProductMap类：

public class ProductoMap : ClassMap<Producto>
{
    public ProductoMap()
    {
        Id(x => x.Id);
        // ... Other Maps and References
        //If you have the id from Stock in your Stock class
        //this will work.
        //References<Stock>( p => p.Stock);
        //If you don't have it, this will work:
        HasOne<Stock>(x => x.Stock).PropertyRef("Name of the column whit the product id in the Stock table");
    }
}

从我的角度来看，第二个选择似乎更好。 无论如何，如果您有一个旧数据库，那么这并不是什么大不了的事情。