Question

在AccountType.cs中我有：

namespace MooDB.Domain
{
    public enum AccountType {Real, Demo, Fictional};
}

在Account.cs中我有：

public class Account : Entity
{        
    public virtual int Id { get; set; }
    public virtual Broker Broker { get; set; }
    public virtual string Name { get; set; }
    public virtual string NickName { get; set; }
    public virtual string AccountNumber { get; set; }
    public virtual Currency Currency { get; set; }
    public virtual AccountType AccountType { get; set; }
    public virtual bool IsActive { get; set; }
    public virtual bool IsDefault { get; set; }
}

在我的Account.hbm.xml中我有

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

  <class name="MooDB.Domain.Account,MooDB" table="accounts">
    <id name="Id" column="accountId" type="Int32" unsaved-value="0">
      <generator class="native" />
    </id>
    <version name="Version" column="version" type="integer" unsaved-value="0" />
    <many-to-one name ="Broker" column="brokerId" not-null="true" class="MooDB.Domain.Broker,MooDB" />
    <property name="Name" column="`name`" type="String" length="50" not-null="true" />
    <property name="NickName" column="nickName" type="String" length="50" not-null="true" />
    <property name="AccountNumber" column="accountNumber" type="String" length="50" not-null="true" />
    <many-to-one name ="Currency" column="currency" not-null="true" class="MooDB.Domain.Currency,MooDB" />
    <property name="AccountType" column="accountType" />
    <property name="IsActive" column="isActive" type="bool" not-null="true" />
    <property name="IsDefault" column="isDefault" type="bool" not-null="true" />
  </class>
</hibernate-mapping>

我的数据库表格如下：

CREATE TABLE [dbo].[accounts](
    [accountId] [int] IDENTITY(1,1) NOT NULL,
    [brokerId] [int] NOT NULL,
    [name] [nvarchar](50) NOT NULL,
    [nickName] [nvarchar](50) NOT NULL,
    [accountNumber] [nvarchar](50) NOT NULL,
    [currency] [char](3) NOT NULL,
    [accountType] [varchar](10) NOT NULL,
    [isActive] [bit] NOT NULL,
    [isDefault] [bit] NOT NULL,
    [version] [int] NOT NULL,
 CONSTRAINT [PK_accounts] PRIMARY KEY CLUSTERED 
(
    [accountId] ASC
)

当我尝试测试帐户检索时，我从NHibernate得到了这个错误：

Test 'Test.RepoTest.CanGetAccountById' failed: NHibernate.Exceptions.GenericADOException : could not load an entity: [MooDB.Domain.Account#1][SQL: SELECT account0_.accountId as accountId3_0_, account0_.version as version3_0_, account0_.brokerId as brokerId3_0_, account0_.[name] as name4_3_0_, account0_.nickName as nickName3_0_, account0_.accountNumber as accountN6_3_0_, account0_.currency as currency3_0_, account0_.accountType as accountT8_3_0_, account0_.isActive as isActive3_0_, account0_.isDefault as isDefault3_0_ FROM accounts account0_ WHERE account0_.accountId=?]
  ----> System.FormatException : Input string was not in a correct format.

我想要做的就是在我的应用程序中列出一个帐户类型列表以进行验证。我不想在我的数据库中有一个查找表。我有什么想法吗？

Answer 1

在AccountType映射上添加type属性，其值为

NHibernate.Type.EnumStringType`1[[MooDB.Domain.AccountType, MooDB]], NHibernate

通过为AccountType指定type属性，我们告诉NHibernate使用自定义 .NET类型和数据库之间的转换类。 NHibernate包括 EnumStringType<T>覆盖枚举值到数据库的转换值，以便存储字符串名称，而不是数值。

Answer 2

我认为NHibernate会默认将枚举作为整数持久化（因为.net枚举基本上是整数的语法糖），除非你另有说明。如果你确实需要它作为字符串，那么你需要实现一个IUserType。类似的示例是将字符串映射到布尔值和is covered here。

使用枚举，您只需更改NullSafeGet和NullSafeSet中的逻辑以映射到您的枚举，可能使用Enum.Parse或TryParse方法。

如何使用NHibernate的Enums？

2 个答案: