ADO .NET DATABSE CONNECTION CODING IN .NET:

  ADO .NET DATABASE CONNECTION CODING IN .NET:

GLOBAL VARIABLES

  static int maxid=0,max=0,wc=0,sum=0,mc=0,rate;

        static String addr="Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\\Universe\\LGdt\\Acmnger.accdb;Persist Security Info=True";

EXECUTE READER - CONNECTED MODEL

        public static int Accmger()

        {

            int max = 0;

            OleDbConnection con = new OleDbConnection(addr);

            con.Open();

            OleDbCommand cmd = new OleDbCommand("select max(id) as maxid from acc",con);

            OleDbDataReader dr = cmd.ExecuteReader();

            while (dr.Read())

            {

                max = Convert.ToInt32(dr["maxid"]);

            }

            con.Close();

           // int maxid=Convert.ToInt32(max);

            return max;

        }

DISCONNECTED MODEL GRIDVIEW

 SqlDataAdapter adapter = new SqlDataAdapter();

        DataSet ds = new DataSet();

        String selecteditem = DropDownList1.Text;

        int i = 0;

        string sql = null;

        string connetionString = @"Data Source=.\SQLEXPRESS;AttachDbFilename=C:\Users\dATA\Documents\Visual Studio 2010\WebSites\WebSite2\App_Data\EmpDet.mdf;Integrated Security=True;User Instance=True";

        sql = "select employee.emp_id,employee.emp_name,employee.designation,employee.salary,dept_list.dept_name from employee INNER JOIN dept_list on employee.dept_id=dept_list.dept_id where dept_list.dept_name='"+selecteditem+"';";

        SqlConnection connection = new SqlConnection(connetionString);

        connection.Open();

        SqlCommand command = new SqlCommand(sql, connection);

        adapter.SelectCommand = command;

        adapter.Fill(ds);

        adapter.Dispose();

        command.Dispose();

        connection.Close();

        GridView2.DataSource = ds.Tables[0];

        GridView2.DataBind();

EXECUTE NON QUERY- 

UPDATE QUERY

OleDbCommand cmd2 = new OleDbCommand("update acc set totalfinal="+ sum +" where id=1", con);

            cmd2.ExecuteNonQuery();

            con.Close();

INSERT QUERY

       

con.Open();

            OleDbCommand cmd = new OleDbCommand("insert into acc(id,purdate,reason,amount) values(" +maxid+ ",'"+purdt+"','" + reason + "'," + rate + ")",con);

            cmd.ExecuteNonQuery();

            con.Close();

Note: Data Adapter may change according to the Database providers

Some ADO .NET Database Provider:

OleDbCommand

SqlCommand