NHibernate的QueryOver預測 - 投影集合到DTO

Question

我想將一個實體的集合投影到DTO中。用簡單的屬性很容易，但與收藏的一個問題：

public class Blog 
{ 
    public string Name {get;set;} 
    public IList<Comments> Comments {get;set;} 
    //... more properties 
} 
public class Comments 
{ 
    public Blog Blog {get;set;} 
    //... more properties 
} 
public class MyDTO 
{ 
    public string BlogName {get;set;} 
    public IList<Comments> {get;set;} 
} 

查詢會有點像：

var dto = _session.QueryOver<Blog>(() => blogAlias) 
          .JoinAlias(x => x.Comments,() => commentsAlias, JoinType.LeftOuterJoin) 
          .Select(
           Projections.Property(() => blogAlias.Reference).WithAlias(() => myDTO.Reference), 
           // what project here to project blogAlias.Comments into myDTO.Comments)) 
          .TransformUsing(Transformers.AliasToBean<MyDTO>() 
          .SingleOrDefault<MyDTO>(); 

編輯UPDATE

我似乎無法得到一個簡單的投影運行，即使沒有變換，並得到： 「索引超出陣列的界限」：

var dto = _session.QueryOver<Blog>(() => blogAlias) 
           .JoinAlias(x => x.Comments,() => commentsAlias, JoinType.LeftOuterJoin) 
           .Select(
            Projections.Property(() => blogAlias.Reference).WithAlias(() => myDTO.Reference), 
Projections.Property(() => blogAlias.Comments).WithAlias(() => myDTO.Comments) 
           .List<object>(); 

Answer 1

我猜這是你應該做的..

更新您的DTO到：

public class MyDTO 
{ 
    public string BlogName {get;set;} 
    public IList<Comments> Comments {get;set;} 
} 

你修改後的查詢：

var dto = _session.QueryOver<Blog>(() => blogAlias) 
      .JoinAlias(x => x.Comments,() => commentsAlias, JoinType.LeftOuterJoin) 
      .Select(Projections.Property(() => blogAlias.Reference).WithAlias(() => myDTO.Reference), 
        Projections.Property(() => blogAlias.Comments).WithAlias(() => myDTO.Comments), 
      .TransformUsing(Transformers.AliasToBean<MyDTO>() 
      .SingleOrDefault<MyDTO>() 

如果不工作，然後

_session.QueryOver<Blog>(() => blogAlias) 
       .JoinAlias(x => x.Comments,() => commentsAlias, JoinType.LeftOuterJoin) 
       .Select(Projections.Property(() => blogAlias.Reference), 
         Projections.Property(() => blogAlias.Comments)) 
       .SingleOrDefault<object[]>() 
       .Select(x=>new MyDTO {BlogName=(string)x[0],Comments=x[1].Select(y=>y.ToString()).ToList())};