Question

我正在尝试使用NHibernate 3.3.3将我的FluentNHibernate映射转换为NHibernate Mapping By-code。目标是升级到NHibernate 3.3.3并减少分发的程序集数量。我将FluentNHibernate的References映射转换为多对一映射时遇到了一些麻烦。

我的许多实体都有需要翻译的说明。为此，我使用包含所有可用语言的这些文本的文本表。我使用文本ID引用文本表，然后在数据访问对象中我过滤所需的语言。这可以使用NHibernate 3.1和FluentNHibernate创建，使用NHibernate 3.3.3和按代码映射但是我只是一个MappingException说：属性映射列数错误：Category.Description类型：Text。

我的新映射在哪里错了？或者这种类型的映射在NHibernate 3.3.3中是不可能的。

这是文本表（SQL-server 2008）。

CREATE TABLE Texts (
    ID         int           NOT NULL,
    languageID nvarchar(10)  NOT NULL,
    Singular   nvarchar(max) NOT NULL,
    Plural     nvarchar(max) NULL,
CONSTRAINT PK_Texts PRIMARY KEY CLUSTERED (ID ASC, languageID ASC)
WITH (PAD_INDEX              = OFF,
      STATISTICS_NORECOMPUTE = OFF,
      IGNORE_DUP_KEY         = OFF,
      ALLOW_ROW_LOCKS        = ON,
      ALLOW_PAGE_LOCKS       = ON) ON [PRIMARY]) ON [PRIMARY]

Text类：

public class Text
{
    public Text(int id, string language, string singular, string plural)
    {
        this.ID = new TextCompositeID(id, language);
        this.Singular = singular;
        this.Plural = plural;
    }
    public TextCompositeID ID { get; private set; }
    public string Plural { get; private set; }
    public string Singular { get; set; }
    public override bool Equals(object obj)
    {
        var text = (Text)obj;
        if (text == null)
        {
            return false;
        }
        return this.ID.Equals(text.ID);
    }
    public override int GetHashCode()
    {
        return this.ID.GetHashCode();
    }
}

这里的例子是Category类：

public class Category
{
    public int ID { get; set; }
    public Text Description { get; set; }
}

Category类的FluentNHibernate xml映射如下所示：

<class xmlns="urn:nhibernate-mapping-2.2"
       mutable="true"
       name="Category"
       lazy="false"
       table="Category"
       where="IsObsolete=0">
    <id name="ID" type="System.Int32">
        <column name="ID" not-null="true" />
        <generator class="native" />
    </id>
    <many-to-one cascade="none"
                 class="Text"
                 name="Description">
        <column name="TextID"
                not-null="true"
                unique="false" />
    </many-to-one>
</class>

由此产生：

public class CategoryMap : ClassMap<Category>
{
    public CategoryMap()
    {
        this.Table("Category");
        Not.LazyLoad();
        this.Where("IsObsolete=0");
        Id(x => x.ID)
            .Column("ID")
            .GeneratedBy.Native()
            .Not.Nullable();
        References(x => x.Description)
            .Column("DescriptionID")
            .Cascade.None()
            .Not.Unique()
            .Not.Nullable();
    }
}

这是我创建的NHibernate ClassMapping：

public CategoryMap()
{
    this.Lazy(false);
    this.Mutable(true);
    this.Table("Category");
    this.Where("IsObsolete=0");
    this.Id(
        x => x.ID,
        map =>
        {
            map.Column("ID");
            map.Generator(Generators.Native);
        });
    this.ManyToOne(
        x => x.Description,
        map =>
        {
            map.Cascade(Cascade.None);
            map.Class(typeof(Text));
            map.Column("TextID");
            map.Fetch(FetchKind.Join);
            map.Lazy(LazyRelation.NoLazy);
            map.ForeignKey("none");
        });
}

从这里我得到这个xml映射：

<class name="Category"
       lazy="false"
       table="Category"
       where="IsObsolete=0">
    <id name="ID"
        column="ID"
        type="Int32">
        <generator class="native" />
    </id>
    <many-to-one name="Description"
                 class="Text"
                 column="TextID"
                 fetch="join"
                 foreign-key="none"
                 lazy="false" />
</class>

Answer 1

我自己找到了答案。我不得不从Text类中删除复合ID：

public class Text
{
    public Text(int id, string language, string singular, string plural)
    {
        this.ID = id;
        this.LanguageID = language;
        this.Singular = singular;
        this.Plural = plural;
    }
    public int ID { get; private set; }
    public string LanguageID { get; private set; }
    public string Plural { get; private set; }
    public string Singular { get; set; }
    public override bool Equals(object obj)
    {
        var text = (Text)obj;
        if (text == null)
        {
            return false;
        }
        return this.ID.Equals(text.ID);
    }
    public override int GetHashCode()
    {
        return this.ID.GetHashCode();
    }
}

类别映射已成为：

public CategoryMap()
{
    this.Lazy(false);
    this.Mutable(true);
    this.Table("Category");
    this.Where("IsObsolete=0");
    this.Id(
        x => x.ID,
        map =>
        {
            map.Column("ID");
            map.Generator(Generators.Native);
        });
    this.ManyToOne(
        x => x.Description,
        map =>
        {
            map.Column("TextID");
            map.Fetch(FetchKind.Join);
            map.ForeignKey("none");
            map.Lazy(LazyRelation.NoLazy);
        });
}

在数据访问对象中，旧的QueryOver查询现在可以获得所需的结果。

NHibernate映射代码ManyToOne与CompositeIdentity

1 个答案: