我有一个如下所示的 Epplus Excel 工作表。
我想按组列(在 A 列中)进行分组,然后选择最大值和最小值。我的 group by
子句中的某些内容不太正确,我收到了一个错误:Cannot apply indexing with [] to ExcelRangeBase
。
var maxMinGrouped = from cells in _dataSheet.Cells["A:H"]
group cells by cells["A:A"].Value into g //pull "Group" column into group
select new
{
Group = cells["A:A"].Value,
MaxDailyIndex = g.Max(c => c.Value),
MinDailyIndex = g.Min(c => c.Value)
};
我正在尝试实现的 SQL。
SELECT Group
,MAX(Col_E) AS MaxDailyIndex
,MIN(Col_E) AS MinDailyIndex
FROM Worksheet
GROUP BY Group
最佳答案
请记住,单元格集合是一个 2x2 矩阵,因此您需要先将单元格分组到行中,然后才能分组到行组中。我对 linq 的查询表示法很生疏,但这里是如何使用点表示法来做到这一点:
[TestMethod]
public void Grouped_Row_Test()
{
//http://stackoverflow.com/questions/30466257/selecting-grouped-max-and-min-in-a-epplus-worksheet-with-linq
var existingFile = new FileInfo(@"c:\temp\Grouped.xlsx");
using (var pck = new ExcelPackage(existingFile))
{
var _dataSheet = pck.Workbook.Worksheets.First();
//Group cells by row
var rowcellgroups = _dataSheet
.Cells["A:H"]
.GroupBy(c => c.Start.Row);
//Now group rows the column A; Skip the first row since it has the header
var groups = rowcellgroups
.Skip(1)
.GroupBy(rcg => rcg.First().Value);
//Reproject the groups for the min/max values; Column E = 5
var maxMinGrouped = groups
.Select(g => new
{
Group = g.Key,
MaxDailyIndex = g.Select(o => o.First(rc => rc.Start.Column == 5)).Max(rc => rc.Value),
MinDailyIndex = g.Select(o => o.First(rc => rc.Start.Column == 5)).Min(rc => rc.Value)
});
maxMinGrouped
.ToList()
.ForEach(mmg => Console.WriteLine("{{Group: \"{0}\", Min={1}, Max={2}}}", mmg.Group, mmg.MinDailyIndex, mmg.MaxDailyIndex));
}
}
在我向您的 excel 表中输入一些随机数据后,它在控制台中给出了这个:
{Group: "3", Min=0, Max=88}
{Group: "4", Min=6, Max=99}
关于c# - 使用 Linq 在 Epplus 工作表中选择分组的最大值和最小值,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/30466257/