如果您有直接的一对多关联到一个组件的集合（即没有 ComponentClass 包装器），那么你可以直接映射它：

  HasMany（x => x.Elements）
 .AsSet（）
 .Table（ElementTable）
 .KeyColumn（KeyColumn ）
 .Cascade.All（）
 .Component（x => 
 {
 x.Map（c => c.Id）; 
 x。 Map（c => c.Time）; 
}）
 .LazyLoad（）; 
 

I have couple of classes and want to map them correctly to database:

public class A
{
    public virtual Guid Id { get; private set; }
    public virtual ComponentClass Component { get; set; }
}

public class ComponentClass 
{
    public virtual IList<B> Elements { get;set; }
}

public class B
{
    public virtual Guid Id { get; private set; }
    public virtual DateTime Time { get; set; }
}

I map them using fluent mappings like that:

public class AMap : ClassMap<A> 
{
    public A() {
        Id(x => x.Id);
        Component(x => x.Component,
                  c => c.HasMany(x => x.Elements).Inverse().Cascade.All());
    }
}

public class BMap : ClassMap<B>
{
    public B() {
        Id(x => x.Id);
        Map(x => x.Time);
    }
}

When I save my entity, I have class A mapped to one table and class B to another as expected. But I have nulls in Component_id column. Can you tell me what am I missing here?

If you have a one-to-many association direct to a collection of components (ie. without the ComponentClass wrapper as per the question) then you can map it directly:

HasMany(x => x.Elements)
    .AsSet()
    .Table("ElementTable")
    .KeyColumn("KeyColumn")
    .Cascade.All()
    .Component(x =>
    {
        x.Map(c => c.Id);
        x.Map(c => c.Time);
    })
    .LazyLoad();