问题描述
|
我有一张表,我需要在该表中根据group by子句对数字列求和来对结果集进行排序。
例如,该表具有销售员ID,订单号和订单值。我想要按累计订单价值列出前10名销售人员。
SQL和LINQ的新手,所以任何建议都将不胜感激!
解决方法
var results = context.Sales.GroupBy(s => s.SalesPersonID)
.Select(g => new {
SalesPersonID = g.Key,Sales = g.Sum(s => s.OrderValue)
})
.OrderByDescending(r => r.Sales)
.Take(10);
, 像这样:
var orders = new[]
{
new Order { SalesPersonId = 1,OrderNumber = 1,OrderValue = 1 },new Order { SalesPersonId = 1,OrderNumber = 2,OrderValue = 2 },new Order { SalesPersonId = 2,};
var topSalesMen = orders
.GroupBy(arg => arg.SalesPersonId)
.Select(arg => new { SalesPersonId = arg.Key,TotalOrderValue = arg.Sum(x => x.OrderValue) })
.OrderByDescending(arg => arg.TotalOrderValue)
.Take(10)
.ToList();