如何映射一个ICompositeUserType [英] How do I map an ICompositeUserType

问题描述

我从移植到NHibernate的流畅简单的工作演示。我现有的NHibernate的映射是这样的：

I am porting a simple working demo from nhibernate to fluent. My existing nhibernate mapping is this:

<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" assembly="MoneyHibernate"
                   namespace="MoneyHibernate">

  <class name="Invoice" table="Invoices">
    <id name="Id">
      <generator class="guid"/>
    </id>
    <property name="Number"/>
    <property name="Customer"/>
    <property name="TotalValue" type="MoneyHibernate.MoneyCompositeUserType,MoneyHibernate">
      <column name="TotalValue_Amount" not-null="true" />
      <column name="TotalValue_Currency" length="3" not-null="true" />
    </property>

  </class>

</hibernate-mapping>

我试图创造equlivilant ClassMap ：

internal class InvoiceMap : ClassMap<Invoice>
{
    public InvoiceMap()
    {
        Id(x => x.Id);
        Map(x => x.Customer);
        Map(x => x.Number);
        Map(x => x.TotalValue)
            .CustomType(typeof (MoneyCompositeUserType))
            .Column("TotalValue_Amount")
            .Column("TotalValue_Currency");
    }
}

但我得到的错误：

But I get the error:

---> NHibernate.MappingException：属性映射有列错号
：MoneyHibernate.Invoice.TotalValue类型：
MoneyHibernate。 MoneyCompositeUserType

---> NHibernate.MappingException: property mapping has wrong number of columns: MoneyHibernate.Invoice.TotalValue type: MoneyHibernate.MoneyCompositeUserType

所以我推测宣布柱两次，是不是这样做的正确方法？

So I presume that declaring column twice is not the correct way to do this?

推荐答案

您在本做了正确的方式，但是，你需要添加 Columns.Clear（）来你的映射之前，像这样的列的手册报关：

You are doing this the right way, however, you need to add Columns.Clear() to your mapping prior to the manual declaration of the columns like this:

Map(x => x.TotalValue)
        .CustomType(typeof (MoneyCompositeUserType))
        .Columns.Clear()
        .Columns.Add("TotalValue_Amount", "TotalValue_Amount");

，否则的nHibernate将除了列集合的复合用户类型映射追加新的列名（因此，错号的列除外）。

Otherwise nHibernate will append the new column names in addition to the column collection for your composite user type mapping (hence the wrong number of columns exception).

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