如果关联的列名相同，则在构建 SessionFactory 时出现 NHibernate 异常属性

Question

我有主表和明细表。两个表中的主键列名称相同：Id.
在构建会话工厂时，出现以下异常：

NHibernate.MappingException: Unable to build the insert statement for class ........Detail1Entity: a failure occured when adding the Id of the class ---> System.ArgumentException: The column 'Id' has already been added in this SQL builder
Parameter name: columnName
   at NHibernate.SqlCommand.SqlInsertBuilder.AddColumnWithValueOrType(String columnName, Object valueOrType)
   at NHibernate.SqlCommand.SqlInsertBuilder.AddColumns(String[] columnNames, Boolean[] insertable, IType propertyType)
   at NHibernate.Persister.Entity.AbstractEntityPersister.GenerateInsertString(Boolean identityInsert, Boolean[] includeProperty, Int32 j)
   --- End of inner exception stack trace ---
   at NHibernate.Persister.Entity.AbstractEntityPersister.GenerateInsertString(Boolean identityInsert, Boolean[] includeProperty, Int32 j)
   at NHibernate.Persister.Entity.AbstractEntityPersister.GenerateInsertString(Boolean[] includeProperty, Int32 j)
   at NHibernate.Persister.Entity.AbstractEntityPersister.PostInstantiate()
   at NHibernate.Persister.Entity.SingleTableEntityPersister.PostInstantiate()
   at NHibernate.Impl.SessionFactoryImpl..ctor(Configuration cfg, IMapping mapping, Settings settings, EventListeners listeners)
   at NHibernate.Cfg.Configuration.BuildSessionFactory()
   at ...........

我有以下表格：

CREATE Table MasterTable1
(
[Id] [INT] IDENTITY (1,1) NOT NULL CONSTRAINT MasterTable1PK PRIMARY KEY,
[MasterData] [VARCHAR] (100)
)

CREATE Table DetailTable1
(
[Id] [INT] IDENTITY (1,1) NOT NULL CONSTRAINT DetailTable1PK PRIMARY KEY,
[MasterId] [INT] NOT NULL CONSTRAINT DetailTable1_MasterTable1_FK FOREIGN KEY REFERENCES MasterTable(MasterId),
[DetailData] [VARCHAR] (100)
)

以下是实体定义：

public class Master1Entity
{
    public virtual int Id { get; set; }
    public virtual string MasterData { get; set; }
}

public class Detail1Entity
{
    public virtual int Id { get; set; }
    public virtual string DetailData { get; set; }

    public virtual Master1Entity Master1 { get; set; }
}

以下是映射：

internal class Master1Map : ClassMapping<Master1Entity>
{
    public Master1Map()
    {
        Table("MasterTable1");

        Id(x => x.Id, im =>
        {
            im.Column("Id");
            im.Generator(Generators.Identity);
        });
        Property(x => x.MasterData);
    }
}

internal class Detail1Map : ClassMapping<Detail1Entity>
{
    public Detail1Map()
    {
        Table("DetailTable1");

        Id(x => x.Id, im =>
        {
            im.Column("Id");
            im.Generator(Generators.Identity);
        });
        Property(x => x.DetailData);

        ManyToOne(x => x.Master1, map => { map.Column("Id"); });
    }
}

如所述，我知道如果我将 [MasterTable1].[Id] 重命名为 [MasterTable1].[MasterId] 并相应地修改实体和映射，这会很好。

但是，我无法更改底层数据库；这是我必须处理的遗留数据库。

此外，这是多对一关系。一个 Master 将有多个 Detail 条目。

有什么方法可以在不更改数据库中的列名的情况下完成这项工作吗？

Answer 1

不要混淆集合映射（期望来自关联 table 的列）与实体映射（期望来自所有者 table 的列）。 ManyToOne 是实体映射，它需要来自 owner table 的列。在您的情况下，Master1 的所有者 table 是 DetailTable1，您需要映射的列是 MasterId:

internal class Detail1Map : ClassMapping<Detail1Entity>
{
...
 ManyToOne(x => x.Master1, map => { map.Column("MasterId"); });

如果关联的列名相同，则在构建 SessionFactory 时出现 NHibernate 异常属性

NHibernate Exception while building SessionFactory if column name is same for association property

nhibernate

nhibernate-mapping

如果关联的列名相同，则在构建 SessionFactory 时出现 NHibernate 异常 属性

NHibernate Exception while building SessionFactory if column name is same for association property

nhibernate

nhibernate-mapping

如果关联的列名相同，则在构建 SessionFactory 时出现 NHibernate 异常属性