Introduction
A DataTable is a class of Disconnected architecture in the .NET Framework. It is
found in the System.Data namespace and represents a single table. We can
create a table and can add columns and rows of that table. Now, we will create
an window application and use the DataTable class.
Create a windows application > create a dataGridView control and write the following
code on the form load event.
using
System;
using
System.Collections.Generic;
using
System.ComponentModel;
using
System.Data;
using
System.Drawing;
using
System.Linq;
using
System.Text;
using
System.Windows.Forms;
namespace
datatable
{
public partial class Form1 :
Form
{
public Form1()
{
InitializeComponent();
}
DataTable dt;
private void
Form1_Load(object sender,
EventArgs e)
{
//Adding Columns
dt = new DataTable();
dt.Columns.Add("ID",
typeof(int));
dt.Columns.Add("Name",
typeof(string));
dt.Columns.Add("Department",System.Type.GetType("System.String"));
dt.Columns.Add("City",
typeof(string));
//Adding Rows
dt.Rows.Add(111, "Alok",
"IT", "Delhi");
dt.Rows.Add(222, "Satish",
"IT", "Jhansi");
dt.Rows.Add(333, "Amitabh",
"Management",
"Noida");
}
}
}
Run the application.
Output
It is a simple example for creating a datatable and adding column and value to
its row. Now we work with its different method.
Working with it's methods
AcceptChanges()
This method saves changes which made with records in a
Datatable.
Take another dataGridView control and a Button. Add below code.
private void btnacceptchanges_Click(object
sender, EventArgs e)
{
dt.AcceptChanges();
dataGridView2.DataSource = dt;
}
Run the application. Make some changes in rows value. I have changed department
name as "cs" for first row and added a new row at last.
Output
Click the "AcceptChanges"
button. Second
dataGridView will show updated record.
Clear()
This method clears
(removes) all data from datatable. Take a button and write the following code on click event.
private void btnclear_Click(object
sender, EventArgs e)
{
dt.Clear();
}
Output
Click the "Clear" button.
It will clear all the data.
Output
Clone()
The clone method copy the
structure of Datatable. Means it copy only schema not full records of Datatable. Take another dataGridView
control and a Button. Add below code.
private void btnclone_Click(object
sender, EventArgs e)
{
DataTable dt1 = dt.Clone();
dataGridView2.DataSource = dt1;
}
Output
Click the "Clone" button.
Output
Copy()
The copy method copy the whole
records with structure of Datatable. Take another dataGridView control and a Button. Write the following code on
button click.
private void btncopy_Click(object
sender, EventArgs e)
{
DataTable dt1 = dt.Copy();
dataGridView2.DataSource = dt1;
}
Output
Click the "copy" button. It will copy all the data with structure of datatable
into another datatable and show records in dataGridView.
Output
GetChanges()
This method does copy of all
records of datatable with changes made with record. Add a button and dataGridView and write the following
code on button click.
private void btnGetChanges_Click(object
sender, EventArgs e)
{
dt.GetChanges();
dataGridView2.DataSource = dt;
}
Output
I have changed some column value like department as "CS" of first row and
city as "Varanasi" for last row.
Click the "GetChanges" button. It will show all
record.
Output
NewRow()
The NewRow method creates a new row with same schema of
datatable. Take a button > Set it's Text property to "NewRow" and write the following code.
private void
btnnewrow_Click(object sender,
EventArgs e)
{
DataRow dr = dt.NewRow();
dr["ID"] = 444;
dr["Name"] =
"Pramod";
dr["Department"]="CS";
dr["City"] =
"Allahabad";
//Add the row to datatable
dt.Rows.Add(dr);
}
Run the application.
Output
Click the "NewRow" button. It will add new row to datatable.
Output
