流利的nHibernate：如何坚持一个属性与公式映射？ [英] fluent nHibernate: How to persist a property which is mapped with Formula?

问题描述

我正在处理一个遗留数据库，而且我们有一个没有意义的字段，但我宁愿不更改数据库模式。

我试图将旧的DB文本字段映射到具有布尔值的类（只需要知道DB文本字段所具有的一个选项）。我可以使用Forumla从数据库中获取布尔值，但我似乎可以将它保存到数据库中。

我的类和当前的流畅映射因为它是：

  public class Bulletin 
 {
 public virtual int Id {get; set;} 
 public virtual bool RegularBulletin {get; set;} 
} 
 
 public class BulletinMapping：ClassMap< Bulletin> 
 {
 public BulletinMapping（）
 {
表（公告）; 
 Id（x => x.Id，ID）。GeneratedBy.Identity（）; 
 $ b $ Map（x => x.RegularBulletin）
 .Formula（case when EmailType ='BULLETIN_B'then 1 else null end）
 .Nullable（）; 
 
 
 
 
 
 
 $ b 
有没有人有关于如何坚持RegularBulletin 
 
 
 
感谢
 Saan 
解决方案
使用一个解决方法 - 创建一个支持字段受保护的虚拟字符串RegularBulletinString ，并使用您的布尔转换公式
  public class Bulletin 
 {
 public virtual int Id {get; set;} 
保护的虚拟字符串RegularBulletinString {get; set;} 
 public virtual bool RegularBulletin 
 {
 get 
 {
 return RegularBulletinString ==BULLETIN_B; 
} 
 set 
 {
 RegularBulletinString = value？ BULLETIN_B：null; 
} 
} 
} 
 
 public class BulletinMapping：ClassMap< Bulletin> 
 {
 public BulletinMapping（）
 {
表（公告）; 
 Id（x => x.Id，ID）。GeneratedBy.Identity（）; 
 
 Map（x => x.RegularBulletinString）
 .Column（EmailType）
 .Nullable（）; 
 IgnoreProperty（x => x.RegularBulletin）; 
 
} 
} 
  
 
I am dealing with a legacy database, and we have a field which doesn't make sense anymore, but I would rather not change the DB schema.

I'm trying to map an old DB text field into a class with a boolean (only need to know about one option that the DB text field has). I can get the boolean value out of the DB using Forumla, but I can seem to get it to save any updates back into the DB.

My class and current fluent mapping for it is:
public class Bulletin
{
    public virtual int Id { get; set;}
    public virtual bool RegularBulletin { get; set;}
}

public class BulletinMapping : ClassMap<Bulletin>
{
    public BulletinMapping()
    {
        Table("Bulletins");
        Id(x => x.Id, "ID").GeneratedBy.Identity();

        Map(x => x.RegularBulletin)
            .Formula("case when EmailType = 'BULLETIN_B' then 1 else null end")
            .Nullable();
    }
}
Does anyone have any ideas about how to persist the RegularBulletin field?

Thanks
Saan
解决方案
I would use a workaround for this- create a backing field protected virtual string RegularBulletinString and use your boolean conversion formula on it.
public class Bulletin
{
    public virtual int Id { get; set;}
    protected virtual string RegularBulletinString { get; set;}
    public virtual bool RegularBulletin 
    { 
       get
       {
          return RegularBulletinString == "BULLETIN_B";
       } 
       set
       {
          RegularBulletinString = value? "BULLETIN_B" : null;
       }
    }
}

public class BulletinMapping : ClassMap<Bulletin>
{
    public BulletinMapping()
    {
        Table("Bulletins");
        Id(x => x.Id, "ID").GeneratedBy.Identity();

        Map(x => x.RegularBulletinString)
            .Column("EmailType")
            .Nullable();
        IgnoreProperty(x=> x.RegularBulletin); 

    }
}


                        
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