EF分组统计

示例

var mainlist = detailviewService.IQueryable().Where(p => p.F_DeleteMark == null)
                .GroupBy(p => new {p.F_FullName,p.F_ProjectYear})
                .Select(p => new
                {
                    p.Key.F_FullName,
                    p.Key.F_ProjectYear,
                    total= p.Sum(w=>w.F_ProjectFee)
                }).ToList();