ต้องการ import excel ไป update ข้อมูลในตาราง แต่เกิดปัญหาตรงที่คอลัมน์ที่เป็นตัวเลขกลายเป็นค่า 0 ทั้งหมด ไม่ทราบว่าเกิดจากอะไรคะ

 For i As Integer = 0 To dgvImportScore.RowCount - 1


            ''strsql = "INSERT INTO Table_1(resub_id,nisit_id,name_score,midterm_score,final_score,project_score,homework_score)"
            ''strsql &= "VALUES('" & re_subid & "' , '" & dgvImportScore.Rows(i).Cells(1).Value & "', '" & dgvImportScore.Rows(i).Cells(4).Value & "', '" & dgvImportScore.Rows(i).Cells(5).Value & "', '" & dgvImportScore.Rows(i).Cells(6).Value & "', '" & dgvImportScore.Rows(i).Cells(7).Value & "', '" & dgvImportScore.Rows(i).Cells(8).Value & "')"


            strsql = "UPDATE Table_1 SET nisit_id = '" & dgvImportScore.Rows(i).Cells(1).Value & "', name_score = '" & dgvImportScore.Rows(i).Cells(4).Value & "', midterm_score = '" & dgvImportScore.Rows(i).Cells(5).Value & "' , final_score = '" & dgvImportScore.Rows(i).Cells(6).Value & "' , project_score = '" & dgvImportScore.Rows(i).Cells(7).Value & "' , homework_score = '" & dgvImportScore.Rows(i).Cells(8).Value & "' WHERE resub_id = '" & re_subid & "' "
            With cmd
                .Connection = con
                .CommandText = strsql
                .CommandType = CommandType.Text
                .ExecuteNonQuery()
            End With

        Next
        MessageBox.Show("เพิ่มคะแนนเรียบร้อยแล้ว")