I have created the sample here please refer it.
I have set the connection String in ApplicationConfig file. Also add the reference of System.Configuration using Add reference on your project.
I am having a DataGridView, Button and three TextBoxes on Form.
Namspaces
using System.Configuration;
using System.Data.SqlClient;
C#
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
this.PopulateDataGridview();
}
private void PopulateDataGridview()
{
this.dataGridView1.AutoGenerateColumns = true;
string conString = ConfigurationManager.ConnectionStrings["conString"].ConnectionString;
string sqlStatment = "SELECT * FROM Students";
using (SqlConnection con = new SqlConnection(conString))
{
using (SqlCommand cmd = new SqlCommand(sqlStatment, con))
{
using (SqlDataAdapter da = new SqlDataAdapter(cmd))
{
DataTable dt = new DataTable();
da.Fill(dt);
this.dataGridView1.DataSource = dt;
this.dataGridView1.AllowUserToAddRows = false;
}
}
}
}
private void Save(string studentName, string course, string country)
{
string conString = ConfigurationManager.ConnectionStrings["conString"].ConnectionString;
string sqlStatment = "INSERT INTO Students(StudentName,Course,Address) VALUES(@StudentName,@Course,@Address)";
using (SqlConnection con = new SqlConnection(conString))
{
using (SqlCommand cmd = new SqlCommand(sqlStatment, con))
{
cmd.Parameters.AddWithValue("@StudentName", studentName);
cmd.Parameters.AddWithValue("@Course", course);
cmd.Parameters.AddWithValue("@Address", country);
con.Open();
cmd.ExecuteNonQuery();
con.Close();
}
}
}
private void btnSave_Click(object sender, EventArgs e)
{
this.Save(this.txtStudentName.Text.Trim(), this.txtCourse.Text.Trim(), txtCountry.Text.Trim());
this.PopulateDataGridview();
}
}
VB
Public Class Form1
Private Sub btnSave_Click(sender As System.Object, e As System.EventArgs) Handles btnSave.Click
Me.Save(Me.txtStudentName.Text.Trim(), Me.txtCourse.Text.Trim(), txtCountry.Text.Trim())
Me.PopulateDataGridview()
End Sub
Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
Me.PopulateDataGridview()
End Sub
Private Sub PopulateDataGridview()
Me.dataGridView1.AutoGenerateColumns = True
Dim conString As String = ConfigurationSettings.AppSettings("conString")
Dim sqlStatment As String = "SELECT * FROM Students"
Using con As New SqlConnection(conString)
Using cmd As New SqlCommand(sqlStatment, con)
cmd.CommandType = CommandType.Text
Using sda As New SqlDataAdapter(cmd)
Using dt As New DataTable()
sda.Fill(dt)
dataGridView1.DataSource = dt
End Using
End Using
End Using
End Using
End Sub
Private Sub Save(studentName As String, course As String, country As String)
Dim conString As String = ConfigurationManager.ConnectionStrings("conString").ConnectionString
Dim sqlStatment As String = "INSERT INTO Students(StudentName,Course,Address) VALUES(@StudentName,@Course,@Address)"
Using con As New SqlConnection(conString)
Using cmd As New SqlCommand(sqlStatment, con)
cmd.Parameters.AddWithValue("@StudentName", studentName)
cmd.Parameters.AddWithValue("@Course", course)
cmd.Parameters.AddWithValue("@Address", country)
con.Open()
cmd.ExecuteNonQuery()
con.Close()
End Using
End Using
End Sub
End Class
SQL
CREATE TABLE [dbo].[Students](
[RollNumber] [int] IDENTITY(1,1) NOT NULL,
[StudentName] [varchar](30) NULL,
[Course] [varchar](30) NULL,
[Address] [varchar](30) NULL
) ON [PRIMARY]
GO
Screenshot