(from item in _dbEntities.Bills
where item.Year == year
select item).GroupBy(x => x.MonthID).Sum(x => x.Phone);
我想按月计算所有水电费账单,比如一月份有 4 笔电费、电话费、水费、煤气费……这些在表中的一行中如何获得这些总和以及按月份 ID 分组
(from item in _dbEntities.Bills
where item.Year == year
select item).GroupBy(x => x.MonthID).Sum(x => x.Phone);
我想按月计算所有水电费账单,比如一月份有 4 笔电费、电话费、水费、煤气费……这些在表中的一行中如何获得这些总和以及按月份 ID 分组
这个返回你每个月所有账单的总和(两个文件 MonthID,Total):
var result = items.Where(b => b.Year == year)
.Select(b => new { b.MonthID, Total = b.Electricity + b.Gas + b.Phone + b.Water })
.GroupBy(b => b.MonthID)
.Select(g => new { MonthID = g.Key, Total = g.Sum(i => i.Total) });
这个返回每个月每个账单的总和(五个字段:MonthID、TotalElectricity、TotalPhone、TotalWater、TotalGas):
var result = items.Where(b => b.Year == year)
.GroupBy(b => b.MonthID)
.Select(
g => new {
MonthID = g.Key,
TotalElectricity = g.Sum(b => b.Electricity),
TotalPhone = g.Sum(b => b.Phone),
TotalWater = g.Sum(b => b.Water),
TotalGas = g.Sum(b => b.Gas)
}
);
你可以试试这个。:
var result= _dbEntities.Bills.Where(b => b.Year == year)
.GroupBy(b => b.MonthId)
.Select(g=> new { MonthId=g.Key,
Phone=g.Sum(b=>b.Phone),
Water = g.Sum(b => b.Water),
Gas = g.Sum(b => b.Gas),
Electricity = g.Sum(b => b.Electricity)
}).ToList();
我将结果保存在具有五个属性的匿名类型中,第一个用于保存MonthId
,其余用于保存该特定月份中所有服务的总和。