HasOne vs References Mapping Fluent NHibernate

问题:

This is the first time I am working with FluentNhibernate Mapping and facing a question of how to reference another table. Any help is appreciated:

I have several tables named CD_varname and all these contain two columns - CODE and DESCR.

I have one main table called Recipient and it has, say two columns, called ALIVE and SEX, both are of type number, and they reference to the tables CD_ALIVE and CD_SEX. If Alive=1 in the Recipient, then we need to get the code and descr from CD_ALIVE table where Code=1.

I have described a Codef class:

public Class Codef {     int Code { get; set; }     string Descr { get; set; } } 

My Recipient Class assigns these to a component. Recipient class looks like this:

 public Class IRecepient {     int ID { get; set; }     Birth Birth {get; set;}     Death Death { get; set; } } 

Where my Birth and Death classes are:

public Class Birth {     DateTime BDate { get; set; }     Codef Sex { get; set; }     Codef Ethnicity { get; set; } //CD_ETHNICITy Table     Codef Race { get; set; } //CD_RACE Table } 

and my Death Class:

public Class Death {     DateTime DeathDate { get; set; }     Codef Alive { get; set; } }    

so, the main column "Alive" in Recipient is actually referencing my Recipient.Death.Alive.Code

I Have a codef mapping class:

   public CodefMapping()          {              Map(x => x.Code, "CODE");              Map(x => x.Descr, "DESCR");          } 

I am trying to do the recipient mapping and this is where I am stuck. Can I do something like this:

 HasOne<CodefMapping>(c => c.Death.Alive)                     .PropertyRef(c => c.Code)                     .PropertyRef(c => c.Descr)                     .WithForeignKey("ALIVE"); 

It is not working :( Any help is greatly appreciated.

Thank you.

回答1:

I think you want to use the References mapping

HasOne means that the 2 entities that you are mapping together share a "mutually exclusive" identifier

http://jagregory.com/writings/i-think-you-mean-a-many-to-one-sir/

回答2:

References is for a property mapping.

public DeathMap() {     References( x => x.Alive );         } 

And you need an Id for codef.

public CodefMapping() {     Id(x => x.Code);     Map(x => x.Descr); } 

The default convention is for column names to match the property name, so you do not have to specify the column names unless they are different.

文章来源: HasOne vs References Mapping Fluent NHibernate