.net - NHibernate mapping table of tables -

i'm trying wrap nhibernate around legacy database (not created me). has can best describe "table of tables," called table_detail. looks this:

column_name  |  table_value    |  table_desc -------------+-----------------+--------------------------------- state        |  ca             |  california state        |  ny             |  new york ... country      |              |  united states country      |  ca             |  canada 

i'm trying map using fluent nhibernate table-per-class-hierarchy strategy. in other words, have tabledetail class, , subclasses state , country. use column_name discriminator.

tabledetailmap.cs:

public class tabledetailmap : classmap<tabledetail> {   public tabledetailmap()   {     table("table_detail");     compositeid()       .keyproperty(x => x.tablevalue, "table_value")       .keyproperty(x => x.columnname, "column_name");     map(x => x.columnname).column("column_name");     map(x => x.tabledesc).column("table_desc");     discriminatesubclassesoncolumn("column_name");   } } 

statemap.cs:

public class statemap : subclassmap<state> {   public statemap()   {     discriminatorvalue("state");   } } 

table_detail has composite key (made of column_name/table_value), , discriminator 1 of fields. problem nhibernate expects both components of composite key referenced in table - shouldn't need be, because 1 defined discriminator.

for example, have address_record table:

line_1           |  city           |  state    |  zip -----------------+-----------------+-----------+---------------- 123 street   |  anytown        |  ca       |  12345 

the problem comes in when try map "state" field state class. state column in address_record refers half of table_detail primary key - table_value part. column_name part "state" - because it's discriminator, i'd expect should provided. nhibernate doesn't think so, , throws exception:

foreign key (fk3d33e87ca66e339c:address_record [state])) must have same number of columns referenced primary key (table_detail [table_value, column_name]) 

how can map nhibernate knows automatically provide "state" value second half of composite key?

if can provide more information, please let me know.

i came so-so fix. in base class map (tabledetailmap.cs), specified discriminator, specified "always select value", so:

public class tabledetailmap : classmap<tabledetail> {   public tabledetailmap()   {     ...snip...      discriminatesubclassesoncolumn("column_name").alwaysselectwithvalue();   } } 

then, in of mapping classes use tabledetail object, had specify use "select" when fetching, so:

public class addressrecordmap : classmap<addressrecord> {   public addressrecordmap()   {     ...snip...      references(x => x.state)       .column("state")       .fetch.select();      ...snip...   } } 

this still did not work in case had 1 of these objects used part of composite id. i'm not sure how fix that, able work around now.