Question

我有以下代码，它按降序列出前3个'名称'，并计算表中出现“名称”的记录数。这工作正常。

Dim top3 = From s In dc.Suggestions
               Group By Name = s.name
               Into t3 = Group, Count()
               Order By Count Descending
               Take 3

我想对此进行修改，以便只计算当前月份中每个“名称”出现的记录数。我可以使用s.dateRaised来获取记录的日期，但我不完全确定如何编写代码以仅获取当前月份的记录？

Answer 1

对卡尔的回答略有修改。我喜欢这个更好一点，因为他的回答不会包含在该月最后一天的最后一分钟内具有dateRaised值的任何内容。

Dim CurrentYear As Integer = DateTime.Today.Year
Dim CurrentMonth As Integer = DateTime.Today.Month

Dim startOfCurrentMonthDate As New DateTime(CurrentYear, CurrentMonth, 1)
Dim startOfNextMonthDate As DateTime = startOfCurrentMonthDate.AddMonths(1)

Dim top3 = From s In dc.Suggestions
           Where s.dateRaised >= startOfCurrentMonthDate AndAlso
                 s.dateRaised < startOfNextMonthDate 
           Group By Name = s.name
           Into t3 = Group, Count()
           Order By Count Descending
           Take 3

Answer 2

首先，获取当月的开头和结尾，如下所示：

Dim CurrentYear As Integer = DateTime.Today.Year
Dim CurrentMonth As Integer = DateTime.Today.Month

Dim startOfCurrentMonthDate As New DateTime(CurrentYear, CurrentMonth, 1)
Dim endOfCurrentMonthDate As DateTime = startDate.AddMonths(1).AddMinutes(-1)

现在，您需要在Where中使用开始日期和结束日期，如下所示：

Dim top3 = From s In dc.Suggestions
           Where s.dateRaised >= startOfCurrentMonthDate And
                 s.dateRaised <= endOfCurrentMonthDate
           Group By Name = s.name
           Into t3 = Group, Count()
           Order By Count Descending
           Take 3

使用Linq - VB获取当月的数据

2 个答案: