NHibernate Mapping - Insert dependency - nhibernate

Question

I have 2 tables
Account
-Id
-AccountName
Contractor
-Id
-AccountId referneces account table
-Code
When I Insert record in Contractor table, it should insert the name of the Contractor in the Account table as Account Name and store the AccountId in the Contractor table.
Can somebody help me in generating the mapping file for this? I tried the following below
Account.hbm
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" namespace="NHibernateService" assembly="NHibernateService">
<class name="Account" table="tbl_Account" entity-name="Account">
<id name="id" column="id">
<generator class="native" />
</id>
<property name="AcName" column="AcName" type="string" length="50" />
</class>
Contractor.hbm
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" namespace="NHibernateService" assembly="NHibernateService">
<class name="Contractor" table="tbl_Contractor" entity-name="Contractor">
<id name="id" column="id">
<generator class="native" />
</id>
<property name="Code" column="Code" type="string" length="50"/>
<bag name="Account" cascade="none" lazy="false">
<key column="Id"/>
<one-to-many entity-name="Account" />
</bag>
</class>
</hibernate-mapping>

Answer 1

The Contractor mapping should be quiet different. The table/schema structure says, that each Contract can have exactly one Account...not more. So there cannot be <bag> but we need <many-to-one>: (see 5.1.10. many-to-one)
<class name="Contractor" table="tbl_Contractor" entity-name="Contractor">
<id name="id" column="id">
<generator class="native" />
</id>
<property name="Code" column="Code" type="string" length="50"/>
<!--<bag name="Account" cascade="none" lazy="false">
<key column="Id"/>
<one-to-many entity-name="Account" />
</bag>-->
<many-to-one name="Account" column="AccountId" cascade="all" >
</class>
The Contractor C# definition should be like
public class Contractor
{
public virtual Account Account { get; set; }
...
And that all together should work for us, because we instructed the NHibernate to cascade changes into second end:
var contract = new Contract {... };
var account = new Account { .. };
contract.Account = account;
session.Save(contract); // both are persisted

Answer 2

It's been a while since I used NHibernate, but I believe you need to configure the cascade for the child collection on parent object which in your case is the Contractor class.
That way, when you do this:
var contractor = new Contractor { Code = "XX" };
contractor.Account.Add(new Account { Name = "Account Name" });
session.Insert(contractor);
NHibernate will generate:
INSERT INTO Account ...
INSERT INTO Contractor ...
You currently have it set to none, you probably want either all or save-update depending on whether you want deletes to cascade too. Check out this page for further info.