Connected Mode in ADO.Net using C# with Example

Connected Mode in ADO.Net using C# with example

In Connected mode in ADO.NET architecture
connection must be open using open method to access data from database and make
connection alive while we perform insert, update, delete and search operation
and after retrieve data from database connection must be close using close
method.

In Connected Mode ADO.NET, DataReader is used to retrieve data from
database and it can hold only single table data while in Disconnected ModeADO.NET, Dataset is used to hold multiple table data.So this is the
limitation of Connected Mode ADO.NET. Because when you constantly trips to the
database for any insert, update, delete and search operation you wish to do.
This creates more traffic to the database.

Also
Read:-
Disconnected Mode ADO.NET using C#

Example:-

Create a Table in Database and windows form in visual studio having
following fields as in screenshot:

using
System;

using
System.Collections.Generic;

using
System.ComponentModel;

using
System.Data;

using
System.Drawing;

using
System.Linq;

using
System.Text;

using
System.Threading.Tasks;

using
System.Windows.Forms;

//use below namespace to connect with ADO.Net

using
System.Data.SqlClient;

namespace
WindowsFormsApplication1

{

public partial class Form1 : Form

{

public Form1()

{

InitializeComponent();

}

// Connected Mode ADO.Net Save button
coding to Save data into Database Table.

private void btnsave_Click(object sender, EventArgs e)

{

// Create object of sqlconnection class.

SqlConnection con=new SqlConnection();

// Set connection string property of
connection object.

con.ConnectionString = @"Data
Source=MALIK\MALIK;Initial Catalog=smalik;Integrated Security=True";

// Open connection using open method.

con.Open();

// Create object of sqlcommand class then
pass connection string and connection object.

SqlCommand cmd=new SqlCommand("insert into tb_test values("+Convert.ToInt32(txtrollno.Text)+",'"+txtfirstname.Text+"','"+txtlastname.Text+"')",con);

// Execute Command using ExecuteNonQuery
method for modification into table.

cmd.ExecuteNonQuery();

// Close connection using close method.

con.Close();

}

private void btnsearch_Click(object sender, EventArgs e)

{

SqlConnection con = new SqlConnection();

con.ConnectionString = @"Data
Source=MALIK\MALIK;Initial Catalog=smalik;Integrated Security=True";

SqlCommand cmd=new SqlCommand("Select * from tb_test where
Rollno="+Convert.ToInt32(txtrollno.Text)+"",con);

con.Open();

SqlDataReader dr =cmd.ExecuteReader();

if (dr.Read())

{

txtfirstname.Text = dr["Firstname"].ToString();

txtlastname.Text = dr["Lastname"].ToString();

}

else

{

MessageBox.Show("Record
not Found");

}

con.Close();

}

private void btndelete_Click(object sender, EventArgs e)

{

SqlConnection con = new SqlConnection();

con.ConnectionString = @"Data
Source=MALIK\MALIK;Initial Catalog=smalik;Integrated Security=True";

SqlCommand cmd = new SqlCommand("Delete from tb_test where
Rollno=" + Convert.ToInt32(txtrollno.Text) + "", con);

con.Open();

int temp=cmd.ExecuteNonQuery();

if (temp > 0)

{

MessageBox.Show("Record
Deleted");

}

else

MessageBox.Show("No
Record found");

con.Close();

}

private void btnupdate_Click(object sender, EventArgs e)

{

SqlConnection con = new SqlConnection();

con.ConnectionString = @"Data
Source=MALIK\MALIK;Initial Catalog=smalik;Integrated Security=True";

SqlCommand cmd = new SqlCommand("Update tb_test set
Firstname='" + txtfirstname.Text + "',Lastname='" + txtlastname.Text + "'", con);

con.Open();

cmd.ExecuteNonQuery();

con.Close();

}

}

}

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