Linq将sql转换为对象列表
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 的tblpage
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 Metadata { get { return (_fields); } set { _fields = value; } } private List _fields = new List(); } public class Field { public FieldNameID {get; set;} public FieldName {get; set;} public FieldValue {get; set;} }
现在，我正在尝试使用linq从数据库中获取数据。
using (DBDataContext context = new DBDataContext()) { List 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(); }
有人可以帮助我如何在列表中获取字段值？
using (DBDataContext context = new DBDataContext()) { List 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(); }
我建议使用DataLoadOptions进行L2S
options.LoadWith(d => d.Metadata);