Добавление данных из DataGridView в базу данных access

Private Sub Button4_Click(sender As Object, e As EventArgs) Handles Button4.Click
        Dim c As New OleDbCommand
        c.Connection = conn
        c.CommandText = "insert into * FROM Spisok"
        Dim da As New OleDbDataAdapter(c)
        Dim dt As DataTable
        conn.Open()
        Dim cb As OleDbCommandBuilder = New OleDbCommandBuilder(da)
        da.InsertCommand = cb.GetInsertCommand()
        dt = New DataTable()
        da.Fill(dt) 'загрузка данных
        da.Update(dt)
        DataGridView2.DataSource = dt.DefaultView
        conn.Close()
    End Sub

Imports System.Data.OleDb
Public Class Form1
    Public conn As OleDbConnection
    Public ReadOnly Property C1 As New OleDbCommand
 
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        For Each lang As Windows.Forms.InputLanguage In System.Windows.Forms.InputLanguage.InstalledInputLanguages
        Next
        CancelButton = Button1
        conn = New OleDbConnection With {
            .ConnectionString =
        "Provider = Microsoft.ACE.OLEDB.12.0;data source=" + IO.Path.Combine(Application.StartupPath, "DB\DBTelSg.accdb")
        }
        conn.Open() ' Открываем соединение 
        RefrechGrid()
        conn.Close()
    End Sub
    Public Sub FillGrid(DataGridView1 As DataGridView, cmd As String, TableName As String)
        C1.Connection = conn
        C1.CommandText = cmd
        Dim ds As New DataSet
        Dim da As New OleDbDataAdapter(C1)
        da.Fill(ds, TableName)
        DataGridView1.DataSource = ds
        DataGridView1.DataMember = TableName
        DataGridView1.Columns("Код").Visible = True
 
    End Sub
    Public Sub RefrechGrid()
 
        FillGrid(DataGridView1, "SELECT * from Spisok ", "Spisok")
 
    End Sub
    Sub AddStr()
        Dim SqlCom As OleDb.OleDbCommand ' Переменная для Sql запросов
        SqlCom = New OleDbCommand($"insert into Spisok([ФИО], [Должность], [Служебный номер], [Личный номер], [Эл Почта]) values('sss', 'fff', 'gggg', 'dddd', 'sdfgh')", conn)
        conn.Open()
        SqlCom.ExecuteNonQuery()
        conn.Close()
    End Sub
 
    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        AddStr()
        RefrechGrid()
    End Sub
End Class

Private Sub Save_Click(sender As Object, e As EventArgs) Handles Button4.Click
        Dim insertCmd = New OleDbCommand() 
        insertCmd.Connection = conn
         Dim s1, s2, s3, s4, s5 As String
      
        conn.Open()
         For i = 0 To DataGridView2.Rows.Count - 1
             s1 = CType(DataGridView2.Rows(i).Cells(0).Value, String)
            s2 = CType(DataGridView2.Rows(i).Cells(1).Value, String)
            s3 = CType(DataGridView2.Rows(i).Cells(2).Value, String)
            s4 = CType(DataGridView2.Rows(i).Cells(3).Value, String)
            s5 = CType(DataGridView2.Rows(i).Cells(4).Value, String)
             insertCmd.CommandText = "insert into Spisok([ФИО], [Должность], [Служебный номер], [Личный номер], [Эл Почта]) values('" & s1 & "', '" & s2 & "', '" & s3 & "', '" & s4 & "', '" & s5 & "')"
             insertCmd.ExecuteNonQuery()
         Next
        conn.Close()
    End Sub

s1 = CType(DataGridView2.Rows(i).Cells(0).Value, String)

s1 = DataGridView2.Rows(i).Cells(0).Value.ToString

insertCmd.CommandText = "insert into Spisok([ФИО], [Должность], [Служебный номер], [Личный номер], [Эл Почта]) values('" & DataGridView2.Rows(i).Cells(0).Value.ToString & "', '" и так далее

    Private Sub Button4_Click(sender As Object, e As EventArgs) Handles Button4.Click
        Dim InsCommand As New OleDbCommand With {
            .Connection = conn
        }
        Dim myTrans As OleDbTransaction
        conn.Open()
        myTrans = conn.BeginTransaction()
        InsCommand.Transaction = myTrans
        Dim s1, s2, s3, s4, s5 As String
 
        For i = 0 To DataGridView2.Rows.Count - 1
            s1 = DataGridView2.Rows(i).Cells(0).Value.ToString
            s2 = DataGridView2.Rows(i).Cells(1).Value.ToString
            s3 = DataGridView2.Rows(i).Cells(2).Value.ToString
            s4 = DataGridView2.Rows(i).Cells(3).Value.ToString
            s5 = DataGridView2.Rows(i).Cells(4).Value.ToString
            InsCommand.CommandText = "INSERT OR IGNORE INTO Spisok([ФИО], [Должность], [Служебный номер], [Личный номер], [Эл Почта]) values('" & s1 & "', '" & s2 & "', '" & s3 & "', '" & s4 & "', '" & s5 & "')"
 
            InsCommand.ExecuteNonQuery()
 
        Next
 
        myTrans.Commit() 'закрываем транзакцию и добавляем данные в базу
        conn.Close()
        myTrans.Dispose()
 
    End Sub

s1 = If(DGV.Rows(i).Cells(0).Value = Nothing, "", DGV.Rows(i).Cells(0).Value.ToString)

  Private Sub Button4_Click(sender As Object, e As EventArgs) Handles Button4.Click
        Dim InsCommand As New OleDbCommand With {
            .Connection = conn
        }
        Dim myTrans As OleDbTransaction
        conn.Open()
        myTrans = conn.BeginTransaction()
        InsCommand.Transaction = myTrans
        Dim s1, s2, s3, s4, s5 As String
 
        For i = 0 To DataGridView2.Rows.Count - 1
            s1 = If(DataGridView2.Rows(i).Cells(0).Value Is Nothing, "", DataGridView2.Rows(i).Cells(0).Value.ToString)
            s2 = If(DataGridView2.Rows(i).Cells(1).Value Is Nothing, "", DataGridView2.Rows(i).Cells(1).Value.ToString)
            s3 = If(DataGridView2.Rows(i).Cells(2).Value Is Nothing, "", DataGridView2.Rows(i).Cells(2).Value.ToString)
            s4 = If(DataGridView2.Rows(i).Cells(3).Value Is Nothing, "", DataGridView2.Rows(i).Cells(3).Value.ToString)
            s5 = If(DataGridView2.Rows(i).Cells(4).Value Is Nothing, "", DataGridView2.Rows(i).Cells(4).Value.ToString)
            InsCommand.CommandText = "INSERT INTO Spisok([ФИО], [Должность], [Служебный номер], [Личный номер], [Эл Почта]) values('" & s1 & "', '" & s2 & "', '" & s3 & "', '" & s4 & "', '" & s5 & "')"
            InsCommand.ExecuteNonQuery()
        Next
        myTrans.Commit() 'закрываем транзакцию и добавляем данные в базу
        conn.Close()
        myTrans.Dispose()
    End Sub

c1.CommandText = $"insert into Spisok(ФИО, Должность, [Служебный номер], [Личный номер], [Эл Почта]) values('{s1}', '{s2}', '{s3}', '{s4}', '{s5}')"