Orario troncato con datatable e MYSQL

Imports System.Data
Imports MySql.Data.MySqlClient
Public Class Form1



    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        Dim conn As New MySqlConnection("server=localhost;username=root;password=12345;database=test")
        conn.Open()

        Dim da As New MySqlDataAdapter("Select * from test", conn)

        Dim dt As New DataTable

        da.Fill(dt)


        DataGridView1.SelectionMode = DataGridViewSelectionMode.FullRowSelect
        DataGridView1.DataSource = dt

        conn.Close()


    End Sub

    Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click



        Dim conn As New MySqlConnection("server=localhost;username=root;password=12345;database=test")
        conn.Open()

        Dim cmd As MySqlCommand
        Dim reader As MySqlDataReader

        cmd = New MySqlCommand("SELECT * FROM test", conn)

        reader = cmd.ExecuteReader

        While reader.Read
            DataGridView2.Rows.Add(reader.GetString(0))
        End While

        conn.Close()
        DataGridView2.Refresh()

    End Sub


End Class