While working with ADO.NET you need to understand the thing why SqlCommand is used.

We have two kind of operations related to database:

1 That will make changes in the database

•  Insert
• Update
• Delete

2 That will not make any change to the database

• Select

Execute no query is the method of SqlCommand class and it used where we want to alter database values.

string connetionString = null;
            SqlConnection cnn ;
            SqlCommand cmd ;
            string sql = null;

            connetionString = "Data Source=ServerName;Initial Catalog=DatabaseName;User ID=UserName;Password=Password";
            sql = "Your SQL Statemnt Here";

            cnn = new SqlConnection(connetionString);
            try
            {
                cnn.Open();
                cmd = new SqlCommand(sql, cnn);
                cmd.ExecuteNonQuery();
                cmd.Dispose();
                cnn.Close();
                MessageBox.Show (" ExecuteNonQuery in SqlCommand executed !!");
            }
            catch (Exception ex)
            {
                MessageBox.Show("Can not open connection ! ");
            }