Question

我有表格订单（姓名，日期，价格）

  horse, 7.5.2012, 100
  cat, 14.5.2012, 50
  horse, 8.5.2012, 70,
  dog, 13.5.2012, 40

我想在星期一出示订单名称和价格总和。输出我想要的东西：

  horse, 100
  cat, 50
  dog, 0

但现在我只有这个：

  horse, 100
  cat, 50

使用此linq查询

  from c in orders
  where (int)c.date.DayOfWeek == this._monday
  group c by c.name into g
  select new {
    Name = g.Key,
    Price = g.Sum(c => c.Price)
  }

你能帮助我吗，我必须改变什么来获得我想要的输出，拜托？：）

Answer 1

首先尝试灌浆，然后对星期一进行过滤

from c in orders  
group c by c.name into g
  select new {
    Name = g.Key,
    Price = g.Where(c => (int)c.date.DayOfWeek == this._monday).Sum(c => c.Price)
  }

Linq：按名称选择所有项目组，计数等于0

1 个答案: