获取本月的所有订单

Question

这是我当前的月份:

model.SalesForMonth = orders.Where(o => o.DateOfPayment.Value.Month == DateTime.Now.Month)
                            .Select(o => o.Total)
                            .Sum();

这不符合预期,因为它也取得了去年同月发生的订单.

当然我可以比较年和月,但必须有一个我不熟悉的更具表现力的解决方案.

我怎样才能使用Linq干净利落地做到这一点？(不确定是否相关但是orders来自实体框架的IQueryable)

Answer 1

最简单的方法是创建一个起点和终点:

// TODO: Consider what time zone you want to consider the current date in
var today = DateTime.Today;
var start = new DateTime(today.Year, today.Month, 1);
var end = start.AddMonths(1); // Exclusive end-point

var query = orders.Where(o => o.DateOfPayment.Value >= start &&
                              o.DateOfPayment.Value < end)
                        .Sum(o => o.Total)