Linq To EF

l簡單查詢：
var result = from c in Entities.Customer select c;

l條件查詢：

  普通linq寫法： var result = from c in Entities.Customer where c.Gender ==‘w’ select c;

  Lambda表達式寫法：   var result = from c in Entities.Customer.Where<Customer>(c =>c.Gender==‘w’);

         排序分頁寫法： IQueryable<Customers> cust10 = (from c in customers

l                                         orderby c.CustomerID

l                                         select c).Skip(0).Take(10);

 

l左外鏈接：能夠的鏈接有Join 和 GroupJoin 方法。GroupJoin組聯接等效於左外部聯接，它返回第一個（左側）數據源的每一個元素（即便其餘數據源中沒有關聯元素）。

l var query = from d in edm.Order_Details

l                   join order in edm.Orders

l                   on d.OrderID equals order.OrderID

l                   select new

l                    {

l                        OrderId = order.OrderID,

l                        ProductId = d.ProductID,

l                        UnitPrice = d.UnitPrice