LINQ到实体查询（1对多）

Question

我需要建立一个查询到实体获得的记录，包括：

• AssetWeapon，
• PersonOut
• 许多与IsIn = True记录，
• 记录数IsIn = False,
• 本月的名称StartTime,

个

记录应当由AssetWeapon

alt text http://www.freeimagehosting.net/uploads/4fee01b48c.png

Answer 1

分组也许这篇文章可以帮助你：

http://msdn.microsoft.com/en-us/vcsharp/aa336746.aspx

看投影算..

Answer 2

在这里我得到了什么最后：

var query = from ta in db.Transactions_Assets.Include("Transaction") 
         let items = new 
         { 
          Weapon = ta.AssetWeapon, 
          Month = ta.Transaction.StartTime.Value.Month, 
          IsIn = ta.IsIn 
         } 
         group items by items.Weapon into g 
         select new { 
          Weapon = g.Key, 
          MonthlyFlow = from m in g 
            group m by m.Month into mg 
            select new { Month = mg.Key, 
               Ins = mg.Count(x => x.IsIn == true), 
               outs = mg.Count(x => x.IsIn == false) 
            } 
         };