如何在 C# 中将 DataTable 行更改为列

How to change DataTable Rows to Columns in C#(如何在 C# 中将 DataTable 行更改为列)

问题描述

如何将数据表行更改为列

How to Change dataTable Rows to Columns

DataTable dt=new DataTable();
dt = getData(); //Pull data from source file

我在数据表中有以下格式行.

I have below format rows in a dataTable.

现在我想将 ANC_TYPE 行更改为列?我怎样才能转换成以下格式?

Now I want change ANC_TYPE rows into columns? How i can convert into below format ?

推荐答案

你想要一个数据透视表:

You want a pivot table :

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;

namespace ConsoleApplication49
{
    class Program
    {

        static void Main(string[] args)
        {
            DataTable dt = new DataTable();
            dt.Columns.Add("OPR_DT", typeof(DateTime));
            dt.Columns.Add("OPR_HR", typeof(int));
            dt.Columns.Add("ANC_TYPE", typeof(string));
            dt.Columns.Add("ANC_REGION", typeof(string));
            dt.Columns.Add("MARKET_RUN_ID", typeof(string));
            dt.Columns.Add("XML_DATE_ITEM", typeof(string));
            dt.Columns.Add("MW", typeof(decimal));
            dt.Columns.Add("GROUP", typeof(int));

            dt.Rows.Add(new object[] { DateTime.Parse("2/23/2017"), 1, "NR", "AS_CAISO_EXP", "DAM", "NS_CLR_PRC", 0.09, 1});
            dt.Rows.Add(new object[] { DateTime.Parse("2/23/2017"), 1, "RD", "AS_CAISO_EXP", "DAM", "RD_CLR_PRC", 2.83, 2 });
            dt.Rows.Add(new object[] { DateTime.Parse("2/23/2017"), 2, "NR", "AS_CAISO_EXP", "DAM", "NS_CLR_PRC", 0.01, 3 });
            dt.Rows.Add(new object[] { DateTime.Parse("2/23/2017"), 2, "RD", "AS_CAISO_EXP", "DAM", "RD_CLR_PRC", 0.1, 4 });

            string[] uniqueAncType = dt.AsEnumerable().Select(x => x.Field<string>("ANC_TYPE")).Distinct().ToArray();

            DataTable pivot = new DataTable();
            pivot.Columns.Add("OPR_DT", typeof(DateTime));
            pivot.Columns.Add("OPR_HR", typeof(int));
            pivot.Columns.Add("ANC_REGION", typeof(string));
            pivot.Columns.Add("MARKET_RUN_ID", typeof(string));
            foreach (string col in uniqueAncType)
            {
                pivot.Columns.Add(col, typeof(string));
            }

            var groups = dt.AsEnumerable()
                .GroupBy(x => new {
                    opr_dt = x.Field<DateTime>("OPR_DT"),
                    opr_hr = x.Field<int>("OPR_HR"),
                    anc_region = x.Field<string>("ANC_REGION"),
                    run_id = x.Field<string>("MARKET_RUN_ID")
                }).ToList();

            foreach (var group in groups)
            {
                DataRow newRow =  pivot.Rows.Add();
                newRow["OPR_DT"] = group.Key.opr_dt;
                newRow["OPR_HR"] = group.Key.opr_hr;
                newRow["ANC_REGION"] = group.Key.anc_region;
                newRow["MARKET_RUN_ID"] = group.Key.run_id;
                foreach (DataRow ancType in group)
                {
                    newRow[ancType.Field<string>("ANC_TYPE")] = ancType.Field<decimal>("MW");
                }


            }

        }
    }


}

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