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C# 使用LINQ为DataTable编写查询_C#_Linq - Fatal编程技术网

C# 使用LINQ为DataTable编写查询

C# 使用LINQ为DataTable编写查询,c#,linq,C#,Linq,需要计算一周中每天记录的数据量 这有什么问题吗 var res = from c in dtHour.AsEnumerable() group c by c.Field<string>("Day Logged") into day let count = day.Count() select new { day_s = day.Count() }; Console.WriteLine(res); var res=from c,单位为dtHour.AsEnumerable() c组

需要计算一周中每天记录的数据量

这有什么问题吗

var res = from c in dtHour.AsEnumerable()
group c by c.Field<string>("Day Logged") into day
let count = day.Count()
select new {
day_s = day.Count()
};
Console.WriteLine(res);
var res=from c,单位为dtHour.AsEnumerable()
c组按c.字段(“记录的日期”)输入日期
让count=day.count()
选择新的{
day\u s=day.Count()
};
控制台写入线(res);

代码未给出所需的输出

怎么了?你有错误吗?错误的数据?你电脑里的一缕烟?什么?更多:数据表的列是手动创建的,我想item.DayLogged将不起作用。我以这种方式修改了它var res=dtHour.AsEnumerable().GroupBy(item=>item.Field(“Day Logged”)).Select(item=>new{DayOfWeek=item.Key,Count=item.Count()});我使用这个查询var res=dtHour.AsEnumerable().GroupBy(item=>item.Field(“记录的日期”)).Select(item=>new{DayOfWeek=item.Key,Count=item.Count()});但是如何打印变量重编码转储的值不是有用的答案。说出你改变了什么,更重要的是,为什么。
var collection = dtHour.AsEnumerable()
      .GroupBy(item => item.Field<string>("Day Logged"))
      .Select(item => new { DayOfWeek = item.Key, Count = item.Count());
Console.WriteLine("Day of week - Count");
foreach(var item in collection)
{
    Console.WriteLine(item.DayOfWeek + " - " + item.Count);
}