c# - Fluent NHibernate HasManyToMany with a discriminator column specifying relationship type -

i'm using fluent nhibernate , i'm trying map many-to-many property bypasses join table. tricky thing is, join table has column determines type of relationship is.

for purpose of question, let's have person table , relation table.

persontable (personid, name, etc) relationtable (relationtype, personida, personidb) 

i want introduce collection property in person class each type of relationship e.g. sons, daughters, etc.

hasmanytomany<person>(x => x.sons)     .table("relationtable")     .parentkeycolumn("personida")     .childkeycolumn("personidb")     .where("relationtype='a_is_father_of_b_boy'");  hasmanytomany<person>(x => x.daughters)     .table("relationtable")     .parentkeycolumn("personida")     .childkeycolumn("personidb")     .where("relationtype='a_is_father_of_b_girl'"); 

the above mappings working reading database not inserting, example:

person john = persondao.getbyname("john"); // sons , daughters loaded fine based on mappings above  john.sons.add(new person("jack"));  // let's add new son persondao.save(john);               // fails because relationtype null 

basically when saving jack john's new son in relationtable need have relationtype populated "a_is_father_of_b_boy", not happening. directive .where("relationtype='a_is_father_of_b_boy'") effective loading not saving.

any ideas? think similar discriminator attribute subclasses.

any appreciated. thanks.

i say, pointed out in comment:

i have relationtable mapped 2 many-to-one references person (as persona , personb). using one-to-many (hasmany), how suggest map sons , daughters (both list<person>) in person class taking account discriminator values above

so pairing object in eyes

public class personrelation {     // pairing table must contain key column, surrogated id     public virtual int id { get; protected set; } // must.       public virtual person parent { get; set; }     public virtual person child { get; set; }     public virtual string relationtype { get; set; } } 

there must key table. inject identity column sql server.. have surrogated (business domain independent) key.

here our person entity

public class person {     ilist<personrelation> _sons;     ilist<personrelation> _daughters;     ..,     public virtual ilist<personrelation> sons      {         { return _sons ?? (_sons = new list<personrelation>()); }         set { _sons = value; }     }     public virtual ilist<personrelation> daughters     {         { return _daughters?? (_daughters= new list<personrelation>()); }         set { _daughters= value; }     } } 

the mapping sons (daughters same):

hasmany<personrelation>(x => x.sons)     // .table("relationtable") // not needed - part of personrleation mapping     .keycolumn("personida")     .where("relationtype='a_is_father_of_b_boy'")     .inverse()     .cascade.alldeleteorphan()  ; 

that work, if assure, when adding son, set relationtype

var parent = ...; // new, loaded var child  = ...; // new, loaded  var relation = new personrelation {     parent = parent;     child  = child;     relationtype = "a_is_father_of_b_boy"; };  parnet.sons.add(relation); 

this must either part of businese layer addson() or poco public method...

note: can map reverse end of relation ... without relationtype filtering:

public class person {     ... above     public virtual ilist<personrelation> parents { get; set; }   hasmany<personrelation>(x => x.parents)     // instead of     // .keycolumn("personida")     // need column     .keycolumn("personidb") ;