Linq 分组GoupBy并且求和Sum
List<Order> orderList = new List<Order>(); for (int i = 0; i < 3; i++) { Order orderEntity = new Order(); orderEntity.OrderID = 100 + i; orderEntity.SellerID = i; orderList.Add(orderEntity); } Order orderEntity2 = new Order(); orderEntity2.OrderID = 400; orderEntity2.SellerID = 4; orderList.Add(orderEntity2); Order orderEntity3 = new Order(); orderEntity3.OrderID = 400; orderEntity3.SellerID = 4; orderList.Add(orderEntity3); //查询分组后的结果 var groupSellerID = from t in orderList group t by new { SellerIDAA = t.SellerID } into g select g; //拿到分组中的最大值 var groupSellerID2 = from t in orderList group t by new { SellerIDAA = t.SellerID } into g select new Order { SellerID = g.Key.SellerIDAA, OrderID = g.Max(v => v.OrderID) }; //各个分组的最大值相加 var groupSellerID3 = (from t in orderList group t by new { SellerIDAA = t.SellerID } into g select new Order { SellerID = g.Key.SellerIDAA, OrderID = g.Max(v => v.OrderID) }).Sum(su => su.OrderID);
-----------------------------------------
public class Order { public int OrderID { get; set; } public int SellerID { get; set; } }
==================================================================
//订单总运费 //按SellerID分组,取每组中运费最大值,最后每组最大值相加。 decimal tradePostFee = (from t in addTradeAndOrderRequstA.requestOrderAddList group t by new { SellerIDAA = t.SellerID } into g select new AddOrderRequest { SellerID = g.Key.SellerIDAA, PostFee = g.Max(v => v.PostFee) }).Sum(su => su.PostFee);
搜索
复制
标签:OrderID,orderList,Sum,Linq,SellerIDAA,new,SellerID,GoupBy,Order From: https://www.cnblogs.com/jankie1122/p/11108735.html