Demo Project

• Open SQL Server .
• Create a new database, with name as demo.
• In that database, create a table named Customers, as shown below.

• Open the previous demo application.
• Add the menu item Database Commands Demo and design the menu as shown below:

• Click  on  Project‖  menu  –> Add  Windows  Form‖.  Enter  the  form  name  as  Insertion. Click on Add.
• Click on Project menu –>Add Windows Form‖. Enter the form name as Deletion. Click on Add.
• Click  on  Project  menu  –>Add  Windows  Form‖.  Enter  the  form  name  as  Updation. Click on Add.
• Double click on menu items one-by-one and write the following code in the Form1.cs:

Program for Menu Items

Form1.cs

private void insertionToolStripMenuItem_Click(object sender, EventArgs e)

{

   Insertion f = new Insertion();

   f.MdiParent = this;

   f.Show();

}

private void deletionToolStripMenuItem_Click(object sender, EventArgs e)

{

   Deletion f = new Deletion();

   f.MdiParent = this;

   f.Show();

}

private void updationToolStripMenuItem_Click(object sender, EventArgs e)

{

   Updation f = new Updation();

   f.MdiParent = this;

   f.Show();

}

• Design the "Insertion" form as follows

Insert

Program for Insert Command Code 

Insertion.cs

using System.Data.SqlClient;

private void button1_Click(object sender, EventArgs e)

{

//Connection impl

SqlConnection cn = new SqlConnection();

cn.ConnectionString = "data source=localhost;user id=sa;password=123;initial 

catalog=demo";

cn.Open();

//Command impl

SqlCommand cmd = new SqlCommand();

cmd.CommandText = "insert into customers values(5,'Arun','Male',8000)";

cmd.Connection = cn;

int n = cmd.ExecuteNonQuery();

if (n > 0)

MessageBox.Show(n + " Row Inserted.");

else

MessageBox.Show("Insertion failed.");

cn.Close();

}

private void button2_Click(object sender, EventArgs e)

{

//Connection impl

SqlConnection cn = new SqlConnection();

cn.ConnectionString = "data source=localhost;user id=sa;password=123;initial 

catalog=demo";

cn.Open();

string gen;

if (radioButton1.Checked == true)

gen = "Male";

else

gen = "Female";

//Command impl

SqlCommand cmd = new SqlCommand();

cmd.CommandText = "insert into customers values(" + textBox1.Text + ",' " + 

textBox2.Text + " ',' " + gen + " '," + textBox3.Text + ")";

cmd.Connection = cn;

int n = cmd.ExecuteNonQuery();

if (n > 0)

MessageBox.Show(n + " Row Inserted.");

else

MessageBox.Show("Insertion failed.");

cn.Close();

} 

Note:  While  you  are  preparing  the  CommandText  with  user-entered  values,  to  remember  the 

concatenation syntax in the above example, remember the following syntax:" + textBox1.Text + "

Deletion

• Design the "Deletion" form as follows:

Program for Deletion Command

Deletion.cs

using System.Data.SqlClient;

private void button1_Click(object sender, EventArgs e)

{

//Connection impl

SqlConnection cn = new SqlConnection();

cn.ConnectionString = "data source=localhost;user id=sa;password=123;initial 

catalog=demo";

cn.Open();

//Command impl

SqlCommand cmd = new SqlCommand();

cmd.CommandText = "delete from customers where customerid=" + textBox1.Text 

+ " ";

cmd.Connection = cn;

int n = cmd.ExecuteNonQuery();

//presentation logic

if (n > 0)

MessageBox.Show(n + " Row Deleted.");

else

MessageBox.Show("Deletion failed.");

cn.Close();

} 

Update

• Design the ―Updation‖ form as follows

Program for Update Command 

Updation.cs

using System.Data.SqlClient;

private void button1_Click(object sender, EventArgs e)

{

//Connection impl

SqlConnection cn = new SqlConnection();

cn.ConnectionString = "data source=localhost;user id=sa;password=123;initial 

catalog=demo";

cn.Open();

string gen;

if (radioButton1.Checked == true)

gen = "Male";

else

gen = "Female"; 

//Command impl

SqlCommand cmd = new SqlCommand();

cmd.CommandText = "update customers set customername= ' " + textBox2.Text + 

" ' ,gender= ' " + gen + " ' ,amount=" + textBox3.Text + " where customerid=" + 

textBox1.Text + " ";

cmd.Connection = cn;

int n = cmd.ExecuteNonQuery();

//presentation logic

if (n > 0)

MessageBox.Show(n + " Row Updated.");

else

MessageBox.Show("Updation failed.");

cn.Close();

}