How to Transpose DataTable in C# ?

In this article we are going to see, How to transpose DataTable in C#? It means we are going to convert DataRow into DataColumn and DataColumn intoDataRow.Following is the simple and self-explanatory example in the form of code comment.

Code Snippet:-

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

namespace BlogsProgram
{

public class TansposeDataTableClass
{

public void TransposeDataTable()
{
// Defined Table as "Employee".
DataTable dt = new DataTable("Employee");
// Defined "EmpID" column as Integer Datatype.
dt.Columns.Add("EmpID", typeof(Int32));
// Defined "EmpName" column as String Datatype.
dt.Columns.Add("EmpName", typeof(string));
// Defined "EmpRank" column as String Datatype.
dt.Columns.Add("Rank", typeof(string));
//Inserting Data into above-defined DataTable
dt.Rows.Add(1, "Raj", "Hyderabad"); // Adding Row 1 to Table
dt.Rows.Add(2, "Shubh", "Nagpur"); // Adding Row 2 to Table
dt.Rows.Add(3, "Neha", "Pune"); // Adding Row 3 to Table
DataTable inputTable = dt;
// Table shown in Figure 1.1
// Calling GenerateTransposedTable() with Datatable as inpute parameter
DataTable transposedTable = GenerateTransposedTable(inputTable);
// Now we got "transposedTable" Transpose table.
//We can use it to bind with grid or for any other operations.
}

private DataTable GenerateTransposedTable(DataTable inputTable)
{
DataTable outputTable = new DataTable();
// Add columns by looping rows
// Header row's first column is the same as in input Table
outputTable.Columns.Add(inputTable.Columns[0].ColumnName.ToString());
// Header row's second column onwards, 'inputTable's first column taken
foreach (DataRow inRow in inputTable.Rows)
{
string newColName = inRow[0].ToString();
outputTable.Columns.Add(newColName);
}
// Add rows by looping columns
for (int rCount = 1; rCount <= inputTable.Columns.Count - 1; rCount++)
{
DataRow newRow = outputTable.NewRow();
// First column is inputTable's Header row's second column
newRow[0] = inputTable.Columns[rCount].ColumnName.ToString();
for (int cCount = 0; cCount <= inputTable.Rows.Count - 1; cCount++)
{
string colValue = inputTable.Rows[cCount][rCount].ToString();
newRow[cCount + 1] = colValue;
}
outputTable.Rows.Add(newRow);
}
return outputTable;
}
}
}