C# DataRow And DataColumn: Update DataTable

In this tutorial, we'll show you how to use DataRow and DataColumn to update data in a DataTable. A DataTable is an in-memory representation of a table that can be used to perform various operations on data without interacting directly with the database.

Set up the environment

Create a new C# Console Application project in Visual Studio and add the following namespaces:

using System;
using System.Data;

Create a sample DataTable

First, let's create a DataTable with some sample data:

static DataTable CreateSampleDataTable()
{
    DataTable table = new DataTable("Employees");

    table.Columns.Add("EmployeeID", typeof(int));
    table.Columns.Add("FirstName", typeof(string));
    table.Columns.Add("LastName", typeof(string));

    table.Rows.Add(1, "John", "Doe");
    table.Rows.Add(2, "Jane", "Smith");

    return table;
}

Update data using DataRow and DataColumn

Create a method called UpdateEmployeeName that updates an employee's name in the DataTable:

static void UpdateEmployeeName(DataTable table, int employeeId, string newFirstName, string newLastName)
{
    DataRow[] foundRows = table.Select($"EmployeeID = {employeeId}");

    if (foundRows.Length > 0)
    {
        DataRow row = foundRows[0];
        row["FirstName"] = newFirstName;
        row["LastName"] = newLastName;
    }
}

Display the DataTable

Create a method called DisplayDataTable to display the contents of the DataTable:

static void DisplayDataTable(DataTable table)
{
    Console.WriteLine("EmployeeID\tFirstName\tLastName");
    Console.WriteLine("---------------------------------------");

    foreach (DataRow row in table.Rows)
    {
        Console.WriteLine($"{row["EmployeeID"]}\t\t{row["FirstName"]}\t\t{row["LastName"]}");
    }
}

Test updating the DataTable

In the Main method, create a DataTable and update the data using the methods we've defined:

static void Main(string[] args)
{
    DataTable employeeTable = CreateSampleDataTable();

    Console.WriteLine("Before update:");
    DisplayDataTable(employeeTable);

    UpdateEmployeeName(employeeTable, 1, "Johnathan", "Doe");

    Console.WriteLine("\nAfter update:");
    DisplayDataTable(employeeTable);

    Console.ReadLine();
}

C# Update DataTable with DataRow Example:

using System;
using System.Data;

class Program
{
    static void Main()
    {
        // Create a DataTable
        DataTable dataTable = new DataTable("MyTable");

        // Define columns
        DataColumn column1 = new DataColumn("ID", typeof(int));
        DataColumn column2 = new DataColumn("Name", typeof(string));

        // Add columns to DataTable
        dataTable.Columns.Add(column1);
        dataTable.Columns.Add(column2);

        // Create a DataRow
        DataRow newRow = dataTable.NewRow();
        newRow["ID"] = 1;
        newRow["Name"] = "John Doe";

        // Add the DataRow to DataTable
        dataTable.Rows.Add(newRow);

        // Modify the DataRow
        DataRow rowToUpdate = dataTable.Rows[0];
        rowToUpdate["Name"] = "Updated Name";

        // Display the DataTable
        foreach (DataRow row in dataTable.Rows)
        {
            Console.WriteLine($"ID: {row["ID"]}, Name: {row["Name"]}");
        }
    }
}

C# DataRow Set Field Value in DataTable:
- Set field values in a DataRow using the SetField method.
```
row.SetField("ColumnName", value);
```
Changing DataColumn Data Type in C# DataTable:
- Modify the DataType property of a DataColumn to change its data type.
```
column.DataType = typeof(newType);
```