c# - 如何映射 ICompositeUserType

Question

我正在将一个简单的工作演示从 nhibernate 移植到 Fluent。我现有的 nhibernate 映射是这样的:

<?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>

我已经尝试创建 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");
    }
}

但是我得到了错误:

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

所以我认为声明列两次不是正确的方法？

Answer 1

您这样做是正确的，但是，您需要在像这样手动声明列之前将 Columns.Clear() 添加到您的映射中:

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

否则，nHibernate 将在您的复合用户类型映射的列集合中附加新的列名(因此出现错误的列数异常)。