Linq to sql进入对象列表

Question

请考虑以下表格：

TblDocument

docID,  levelID, name 
101,    201,     AAA 
102,    201,     BBB 
103,    201,     CCC 
104,    202,     DDD 
105,    202,     EEE 

网页

pgID, docID, pgNo
1,    101,   1
2,    102,   1
3,    102,   2
4,    103,   1
5,    104,   1
6,    105,   1

TblFieldName

fieldNameID, levelID, fieldName  
1,           201,     WrittenBy  
2,           201,     VerifiedBy 
3,           201,     DocumentName

TblFieldValue

docID,  fieldNameID, fieldValue 
101,    1,           James 
101,    2,           Bond  
101,    3,           Essay on something  
102,    1,           Krister
102,    2,           Holm
102,    3,           Dame it or not!  

---

public class Document
{
  public int DocID {get; set;}
  public int LevelID {get; set;}
  public string Name {get; set;}

  public List<Field> Metadata
  {
     get { return (_fields); }
     set { _fields = value; }
  }       
  private List<Field> _fields = new List<Field>();
}


public class Field
    {
      public FieldNameID {get; set;}
      public FieldName {get; set;}
      public FieldValue {get; set;}
    }

现在，我试图使用运行良好的linq从数据库中获取数据。

using (DBDataContext context = new DBDataContext())
{
  List<Document> doc  = (from d in context.TblDocuments
     join p in context.TblPages on d.docID equals p.docID into dpgrp
     from dp in dpgrp.Where(f => f.docID == d.docID).DefaultIfEmpty()
     where d.levelID == 201
     select new Document
     {
       DocumentID = d.docID,
       LevelID = d.levID
     }).ToList<Document>();
 }

有人可以帮我如何获取列表中的字段值吗？

using (DBDataContext context = new DBDataContext())
{
  List<Document> doc  = (from d in context.TblDocuments
     join p in context.TblPages on d.docID equals p.docID into dpgrp
     from dp in dpgrp.Where(f => f.docID == d.docID).DefaultIfEmpty()
     where d.levID == 201
     select new Document
     {
       DocumentID = d.docID,
       LevelID = d.levID
       Metadata = ???????            // how to achieve this? as it is a list
     }).ToList<Document>();
 }

Answer 1

我建议对L2S使用DataLoadOptions

options.LoadWith<Document>(d => d.Metadata);