[轉貼] LINQ - IN 原來很簡單

出處：http://www.dotblogs.com.tw/dc690216/archive/2009/09/13/10606.aspx

之前有發表過一篇，LINQ的IN與NOT IN，看起來似乎有點麻煩，並不是那麼的好用，那麼小弟再來寫寫IN與NOT IN的簡單用法。(以Northwind的Orders為範例)

1.LINQ - IN

Code：

MyDataContext db = new MyDataContext();

string[] strArray = new string [] { "ALFKI", "ANATR" };

var result = from c in db.Orders
where strArray.Contains(c.CustomerID)
orderby c.CustomerID ascending
select c;

dataGridView1.DataSource = result.ToList();

SQL Code：

SELECT [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]
WHERE [t0].[CustomerID] IN (@p0, @p1)

結果：



2.LINQ - NOT IN

Code：

MyDataContext db = new MyDataContext();

string[] strArray = new string[] { "ALFKI", "ANATR" };

var result = from c in db.Orders
where !strArray.Contains(c.CustomerID)
orderby c.CustomerID ascending
select c;

dataGridView1.DataSource = result.ToList();

SQL Code：

SELECT [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]
WHERE NOT ([t0].[CustomerID] IN (@p0, @p1))
ORDER BY [t0].[CustomerID]

結果：



是否簡單多了呢!? 看起來確實比之前發的那一篇還要簡單，供大家參考。