fluent nhibernate mapping - nhibernate

Question

I am trying to create a map to get results as like from below query.
I am having hard time to get set Product mapping to set References to Product_Line on 3 columns as in where condition. How can I achieve this using fluent?
Product table: cId, ProjID, Line, etc., columns
Product_Line table: cId, ProjID, Line, etc., columns
select f.* from Product f
join Product_Line v on f.cId = v.CId and f.ProjID = v.ProjID and f.line = v.line
Thanks in Advance.
RajeshC
First, thank you for looking into it and Here with more info:
//Req: I want to query product such that if there is NO ProductLine, then I want to create a ProductLine, if there is one, then I'll update it.
public class ProductMap : ClassMap<Product>
{
Id(x => x.Id);
Map(x => x.CustomerId, "CustId");
Map(x => x.ProjId, "PROJId");
Map(x => x.LineNumber, "LineNumber");
Map(x => x.ReportType, "ReportType");
// Reference to Product_Line? - this reference should be based on three columns (custId, ProjId, LineNumber)
References(x => x.Line);
}
public class ProductLineMap : ClassMap<ProductLine>
{
Table("Product_Line");
Map(x => x.CustomerId, "CustId"); //same column as Product.CustId
Map(x => x.ProjId, "PROJId"); //Same as Product.ProjId
Map(x => x.LineNumber, "LINENUMBER"); //Same as Product.LineNumber
//etc.,
//for me, this reference is not needed as I need from Product to ProductLine - one way.
//References(x => x.Product).Column("ProjId") //
}

Answer 1

We could give you a much better answer if you showed us your C# code and wrapped the SQL in < code > tags... Here's my guess at what I think you want:
public class ProductMap : ClassMap<Product>
{
Id(x => x.Id);
References(x => x.Line); // Reference to Product_Line?
// etc.
}
public class ProductLineMap : ClassMap<ProductLine>
{
Table("Product_Line");
Id(x => x.Id).Column("cId");
References(x => x.Product).Column("ProjId")
}