#眉標=VS2008、、
#副標=體驗新一代整合開發環境(19)
#大標=多用途查詢語言LINQ資料操作實務
#作者=文／圖 王寧疆




===<反灰>=============
string startFolder = @"C:\Program Files\Microsoft Visual Studio 9.0"; //指定欲搜尋的資料夾
IEnumerable<System.IO.FileInfo> fileList = 
GetFiles(startFolder); //呼叫GetFiles方法，取得資料夾下所有的檔案名稱
System.Text.RegularExpressions.Regex searchTerm = new System.Text.RegularExpressions.Regex(
@"Visual (Basic|C#|C\+\+|SourceSafe|Studio)");	//建立Regex類別的物件，指定欲搜尋的內容
var queryMatchingFiles =from file in fileList
   where file.Extension == ".htm"
   let fileText = System.IO.File.ReadAllText(file.FullName)
   let matches = searchTerm.Matches(fileText)
   where searchTerm.Matches(fileText).Count > 0
   select new
   {
     name = file.FullName,
     matches = from System.Text.RegularExpressions.Match match in matches
      select match.Value
   }; //搜尋副檔名為.HTM的檔案內容是否有出現指定的字串
  foreach (var v in queryMatchingFiles) //取得所有內容包含指定字串內容的檔案名稱
  {
     Control.WriteLine(v.name); //顯示檔案名稱
  }
==<end>==============





===<反灰>=============
IEnumerable<System.IO.FileInfo> GetFiles(string path)
{
   if (!System.IO.Directory.Exists(path))	//如果指定的資料夾不存在
     throw new System.IO.DirectoryNotFoundException(); //引發例外
   string[] fileNames = null;	 //存放檔案名稱的陣列
   List<System.IO.FileInfo> files = 
new List<System.IO.FileInfo>();	//建立存放FileInfo類別的物件的集合
   fileNames = System.IO.Directory.GetFiles(path, "*.*", 
     SearchOption.AllDirectories); //取出資料夾(包含子資料夾在內)底下所有的檔案名稱
   foreach (string name in fileNames) //取出所有的檔案名稱
   {
     files.Add(new System.IO.FileInfo(name));	//依據檔案名稱建立FileInfo類別的名稱，
//再加入到名稱為files的集合中
   }
   return files; //傳回名稱為files的集合
}
==<end>==============






===<反灰>=============
public class dbOrders
{
  public IQueryable BindOrders(int startRowIndex, int maximumRows)//具分頁功能的查詢方法
  {
    NorthwindDataContext dc = new NorthwindDataContext();	//建立DataContext類別的物件
    var query = from order in dc.Orders
      select order;	 //取出Orders資料表的記錄
    return query.Skip(startRowIndex).Take(maximumRows);	//從startRowIndex編號起，取出maximumRows筆記錄
  }
  public int GetOrderCount()	 //查詢Orders的資料筆數
  {
    NorthwindDataContext dc = new NorthwindDataContext();	//建立DataContext類別的物件
    return (from order in dc.Orders
     select order).Count(); //傳回Orders的資料筆數
  }
}
==<end>==============






==<反灰>===========
exec sp_executesql N'SELECT [t1].[OrderID], [t1].[CustomerID], [t1].[EmployeeID], [t1].[OrderDate], [t1].[RequiredDate], [t1].[ShippedDate], [t1].[ShipVia], [t1].[Freight], [t1].[ShipName], [t1].[ShipAddress], [t1].[ShipCity], [t1].[ShipRegion], [t1].[ShipPostalCode], [t1].[ShipCountry]
FROM (
    SELECT ROW_NUMBER() OVER (ORDER BY [t0].[OrderID], [t0].[CustomerID], [t0].[EmployeeID], [t0].[OrderDate], [t0].[RequiredDate], [t0].[ShippedDate], [t0].[ShipVia], [t0].[Freight], [t0].[ShipName], [t0].[ShipAddress], [t0].[ShipCity], [t0].[ShipRegion], [t0].[ShipPostalCode], [t0].[ShipCountry]) AS [ROW_NUMBER], [t0].[OrderID], [t0].[CustomerID], [t0].[EmployeeID], [t0].[OrderDate], [t0].[RequiredDate], [t0].[ShippedDate], [t0].[ShipVia], [t0].[Freight], [t0].[ShipName], [t0].[ShipAddress], [t0].[ShipCity], [t0].[ShipRegion], [t0].[ShipPostalCode], [t0].[ShipCountry]
    FROM [dbo].[Orders] AS [t0]
    ) AS [t1]
WHERE [t1].[ROW_NUMBER] BETWEEN @p0 + 1 AND @p0 + @p1
ORDER BY [t1].[ROW_NUMBER]',N'@p0 int,@p1 int',@p0=30,@p1=10
==<END>===========






==<反灰>===========
class Products
{
  public int ProductID { get; set; }
  public int SupplierID { get; set; }
  public string CompanyName { get; set; }
}
==<END>===========






==<反灰>===========
private IEnumerable<Products> GetProducts(int ProductID)
{
//LINQ對northwindDataSet中的Products和Suppliers進行JOIN操作，並讀取Products的ProductID欄位與Suppliers的SupplierID和CompanyName欄位當做結果
  var DataSet = from p in northwindDataSet.Products
   join s in northwindDataSet.Suppliers
   on p.SupplierID equals s.SupplierID
   where p.ProductID == ProductID
   select new Products
   {
     ProductID = p.ProductID,
     SupplierID = p.SupplierID,
     CompanyName = s.CompanyName
   };
  return DataSet.ToList(); //傳回JOIN運算結果
}
==<END>===========




==<反灰>===========
dataGridView1.DataSource = GetProducts(產品編號);
==<END>===========





==<反灰>===========
from o in Orders
where o.CustomerID=="ALFKI" 
select o
==<END>===========