Обновление dataGridView

private void buttonInsert_Click(object sender, EventArgs e)
{
    SecondForm dlg = new SecondForm();
    if (P.a)
        dlg.ShowDialog();
    this.dataGridView1.Refresh();   
    //this.dataGridView1.Update();
    //data_show();
}

private void data_show()
{
    P.MyConnection.Open();
    string stm = "SELECT name_project_title,number_channels FROM project_title";
    var cmd = new SQLiteCommand(stm, P.MyConnection);
    rdr=cmd.ExecuteReader();
    while( rdr.Read()) {
        dataGridView1.Rows.Insert(0, rdr["name_project_title"].ToString() , rdr["number_channels"].ToString());
    }
    try
    {
        dataGridView1.CurrentCell = dataGridView1[0, 0];   /*курсор*/
    }
    catch (Exception ex)
    {
 
    }
    P.MyConnection.Close();
}

private void data_show()
{
    P.MyConnection.Open();
    DataTable tbl= new DataTable("Titl");
    tbl.Columns.Add("Название проекта");
    tbl.Columns.Add("Количество каналов");
    string stm = "SELECT name_project_title,number_channels FROM project_title";
    var cmd = new SQLiteCommand(stm, P.MyConnection);
    rdr=cmd.ExecuteReader();
    while( rdr.Read()) {
        tbl.Rows.Add( rdr["name_project_title"].ToString() , rdr["number_channels"].ToString());
        dataGridView1.DataSource = tbl;
    }
    try
    {
        dataGridView1.CurrentCell = dataGridView1[0, 0];   /*курсор*/
    }
    catch (Exception ex)
    {
 
    }
    P.MyConnection.Close();
}

while( rdr.Read()) {
    tbl.Rows.Add( rdr["name_project_title"].ToString() , rdr["number_channels"].ToString());
}
dataGridView1.DataSource = tbl;

while( rdr.Read()) {
    tbl.Rows.Add( rdr["name_project_title"].ToString() , rdr.GetValue(1));
}
dataGridView1.DataSource = tbl;

using System;
using System.Data;
using System.Windows.Forms;
 
namespace OdinNastya
{
    public partial class Form1 : Form
    {
        Timer timer = new Timer();
        DataSet ds = new DataSet();
        DataTable table;
 
        public Form1()
        {
            InitializeComponent();
 
            table = ds.Tables.Add("table");
 
            table.Columns.Add(new DataColumn("id", typeof(long)));
            table.Columns.Add(new DataColumn("value", typeof(string)));
 
            dataGridView1.DataSource = ds;
            dataGridView1.DataMember = "table";
 
            timer.Interval = 500;
            timer.Tick += Timer_Tick;
            timer.Start();
        }
 
        private void Timer_Tick(object sender, EventArgs e)
        {
            table.Rows.Add(DateTime.Now.Ticks, DateTime.Now.ToLongTimeString());
        }
    }
}

using System;
using System.Data;
using System.Data.SQLite;
using System.Windows.Forms;
 
namespace OdinNastya
{
    public partial class Form1 : Form
    {
        SQLiteConnection connection;
        DataSet ds = new DataSet();
        DataTable table;
 
        public Form1()
        {
            InitializeComponent();
 
            table = ds.Tables.Add("example");
            var columnId = table.Columns.Add("id", typeof(long));
            columnId.AutoIncrement = true;
            columnId.Unique = true;
            table.PrimaryKey = new DataColumn[] { columnId };
            table.Columns.Add("value", typeof(string));
 
            connection = new SQLiteConnection("Data Source=:memory:");
            connection.Open();
 
            CreateTable(connection);
            InsertRecord(connection, "1");
            InsertRecord(connection, "10");
            InsertRecord(connection, "100");
            InsertRecord(connection, "1000");
 
            LoadData(connection);
        }
 
        private void CreateTable(SQLiteConnection connection)
        {
            var command = new SQLiteCommand(@"
CREATE TABLE example (
    id INTEGER PRIMARY KEY,
    value TEXT NOT NULL
);
",
                connection);
            command.ExecuteNonQuery();
        }
 
        private void InsertRecord(SQLiteConnection connection, string value)
        {
            var command = new SQLiteCommand(connection);
            command.CommandText = "insert into example (value) values (@value);";
            command.Parameters.Add("value", DbType.String).Value = value;
            command.ExecuteNonQuery();
        }
 
        private void LoadData(SQLiteConnection connection)
        {
            var command = new SQLiteCommand("select * from example", connection);
            var adapter = new SQLiteDataAdapter(command);
            adapter.Fill(table);
            dataGridView1.DataSource = table;
        }
 
        private void buttonAdd_Click(object sender, EventArgs e)
        {
            InsertRecord(connection, DateTime.Now.ToLongTimeString());
            //dataGridView1.DataSource = null;
            LoadData(connection);
        }
    }
}