Fluent NHibernate：將NULL插入到FK列

Question

我必須在我的數據庫中有兩個表：患者和地址。他們通過患者的地址和CorrespodencyAddress字段處於一對一關係。

這裏是患者代碼：

public class Patients 
{ 
    public virtual int Id { get; protected set; } 
    public virtual int? IndividualId { get; set; } 
    public virtual string First_Name { get; set; } 
    public virtual string Last_Name { get; set; } 
    public virtual string Pesel { get; set; } 
    public virtual string Gender { get; set; } 
    public virtual string Height { get; set; }  //wzrost 
    public virtual string Comments { get; set; }  //uwagi 

    public virtual Adresses Address { get; set; } 
    public virtual Adresses CorrespondencyAddress { get; set; } 
    public virtual StudyPayer DefaultPayer { get; set; } 

    public virtual DateTime? BirthDate { get; set; } 
    public virtual string PhoneNumber { get; set; } 

    public virtual DateTime? RegistrationDate { get; set; } 
    public virtual IList<Studies> Studies { get; set; } 

    public Patients() 
    { 
     Studies = new List<Studies>(); 
    } 

    public virtual void AddAddress(Adresses adresses) 
    { 
     adresses.Patient = this; 
     Address = adresses; 
    } 

    public virtual void AddStudy(Studies studies) 
    { 
     studies.Patient = this; 
     Studies.Add(studies); 
    } 
} 


public class PatientsMap :ClassMap<Patients> 
{ 
    PatientsMap() 
    { 
     Id(x => x.Id).GeneratedBy.Identity(); 
     Map(x => x.IndividualId); 
     Map(x => x.First_Name); 
     Map(x => x.Last_Name); 
     Map(x => x.Pesel); 
     Map(x => x.Gender); 

     if (ConfigurationMap.DbType == DbType.PostgreSql) 
     { 
      Map(x => x.RegistrationDate).Nullable(); 
      Map(x => x.BirthDate).Nullable(); 
     } 

     if (ConfigurationMap.DbType == DbType.MsSql) 
     { 
      Map(x => x.RegistrationDate).CustomSqlType("datetime2").Nullable(); 
      Map(x => x.BirthDate).CustomSqlType("datetime2").Nullable();  
     } 

     Map(x => x.PhoneNumber); 
     Map(x => x.Height); 
     Map(x => x.Comments); 

     References(x => x.Address).Cascade.All(); 
     References(x => x.CorrespondencyAddress).Cascade.All(); 

     References(x => x.DefaultPayer); 
     HasMany(x => x.Studies).Cascade.All().KeyColumn("patient_id"); 
    } 
} 

下面是地址

public class Adresses 
{ 
    public virtual int Id { get; protected set; } 
    public virtual string Street { get; set; } 
    public virtual string HomeNumber { get; set; } 
    public virtual string PostalCode { get; set; } 
    public virtual string City { get; set; } 
    public virtual string Country { get; set; } 

    public virtual Patients Patient { get; set; } 

    public virtual void AddPatient(Patients patient) 
    { 
     patient.Address = this; 
     Patient = patient; 
    } 

}  


public class AdressesMap : ClassMap<Adresses> 
{ 
    AdressesMap() 
    { 
     Id(x => x.Id).GeneratedBy.Identity(); 
     Map(x => x.HomeNumber); 
     Map(x => x.Street); 
     Map(x => x.PostalCode); 
     Map(x => x.City); 
     Map(x => x.Country); 

     References(x => x.Patient).Cascade.All(); 
    } 
} 

我們都知道有時CorrespodencyAddress相同地址碼的話，我想插入NULL到CorrespodencyAddress並且它將意味着它是相同的地址。

我該如何做到這一點？

如果我不喜歡下面，我得到的「可空對象必須有一個值」在運行時異常：

Patients p = new Patients(); 
p.CorrespondencyAddress = null; 

Answer 1

你應該改變這樣的：

References(x => x.Address).Cascade.All(); 
References(x => x.CorrespondencyAddress).Cascade.All(); 

進入這個（見.Nullable()設置）

References(x => x.Address).Cascade.All(); 
References(x => x.CorrespondencyAddress).Nullable().Cascade.All(); 

Check al L時可設置here（向下滾動到流利NHibernate的等效）

而且檢查：

public class Patients 
{ 
    ... 
    public virtual int? IndividualId { get; set; } 

，這映射：

Map(x => x.IndividualId); 

這應該是

Map(x => x.IndividualId).Nullable();