问题
I'm trying to learn NHibernate 3.2 built-in mapping by code api
(NOT Fluent NHibernate). Can you help me to map a one-to-one(or zero) relationship between these entities please?
NOTE: I googled the question, also I search the SOF, all examples are using Fluent API or xml; I'm trying to use built-in mapping api in NHibernate 3.2
public class Person {
public virtual int Id { get; set; }
public virtual string FirstName { get; set; }
public virtual string LastName { get; set; }
// can be null
public virtual Address Address { get; set; }
}
public class Address {
public virtual int Id { get; set; }
public virtual string Line1 { get; set; }
public virtual string Line2 { get; set; }
public virtual string City { get; set; }
// can not be null
public virtual Person Person { get; set; }
}
Thanks in advanced.
UPDATE:
Primary key strategy is here:
Id(
t => t.Id,
t => {
t.Generator(Generators.HighLow, g => g.Params(new { max_low = 100 }));
t.Column(typeof(TEntity).Name + "Id");
});
回答1:
Depending on what you ACTUALLY want- a one-to-one map or a many-to-one map may answer your question. Please see this link for one-to-one if you need a truly unique bi-directional constraint: http://notherdev.blogspot.com/2012/01/mapping-by-code-onetoone.html
One-to-ones are normally a bad strategy because it makes sense to just put the columns all on one table in almost all cases, and separate them via a component mapping if you need them to be separate entities in your domain. The typical way to separate them in the domain AND the data models is to use a many-to-one with a unique constraint tying back up to the parent and this is a common pattern.
For tips and hints on general 3.2 mappings, this resource has been a ton of help for me: http://notherdev.blogspot.com/2012/02/nhibernates-mapping-by-code-summary.html
来源:https://stackoverflow.com/questions/9562507/one-to-one-mapping-in-nhibernate-3-2-mapping-by-code