Visual Basic

1. Connect to the Access database - see Access connection strings - ConnectionStrings.com[^] ;
2. Load the data you want to export using the OleDb classes - OleDbCommand Class (System.Data.OleDb) | Microsoft Docs[^] ;
3. Export the data to an Excel file;

{Retrieving the COM class factory for component with CLSID {00020819-0000-0000-C000-000000000046} failed due to the following error: 80040154 Class not registered (Exception from HRESULT: 0x80040154 (REGDB_E_CLASSNOTREG)).}

Private Sub excel_Click(sender As Object, e As EventArgs) Handles excel.Click
    Threading.Thread.CurrentThread.CurrentCulture = Globalization.CultureInfo.CreateSpecificCulture("en-US")
    Dim Xa As New Excel.Application
    Dim Wb As New Excel.Workbook
    Dim Ws As New Excel.Worksheet

    Wb = Xa.Workbooks.Add
    Ws = Wb.Worksheet("Sheet1")

    Ws.Cells(0, 0) = "Column_1"
    Ws.Cells(0, 1) = "Column_2"

    Ws.Cells(1, 0) = "Value_1"
    Ws.Cells(1, 1) = "Value_2"

    Xa.Visible = True
    Ws = Nothing : Wb = Nothing : Xa = Nothing

End Sub

Considerations for server-side Automation of Office[^]

Microsoft does not currently recommend, and does not support, Automation of Microsoft Office applications from any unattended, non-interactive client application or component (including ASP, ASP.NET, DCOM, and NT Services), because Office may exhibit unstable behavior and/or deadlock when Office is run in this environment.

 Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click

        Dim xlApp As Excel.Application
        Dim xlWorkBook As Excel.Workbook
        Dim xlWorkSheet As Excel.Worksheet
        Dim misValue As Object = System.Reflection.Missing.Value
        Dim i As Integer
        Dim j As Integer

        xlApp = New Excel.Application
        xlWorkBook = xlApp.Workbooks.Add(misValue)
        xlWorkSheet = xlWorkBook.Sheets("Sheet1")

        For i = 0 To dgvData.RowCount - 2
            For j = 0 To dgvData.ColumnCount - 1
                xlWorkSheet.Cells(i + 1, j + 1) = dgvData(j, i).Value.ToString()
            Next
        Next

        xlWorkSheet.Columns.AutoFit()
        xlWorkSheet.Rows.AutoFit()
        xlWorkSheet.SaveAs("C:\xxx\xxx.xlsx")
        xlWorkBook.Close()
        xlApp.Quit()

        releaseObject(xlApp)
        releaseObject(xlWorkBook)
        releaseObject(xlWorkSheet)

        MessageBox.Show("xxx C:\xxx\xxx.xlsx", "xxx", MessageBoxButtons.OK, MessageBoxIcon.Information)

    End Sub

    Private Sub releaseObject(ByVal obj As Object)
        Try
            System.Runtime.InteropServices.Marshal.ReleaseComObject(obj)
            obj = Nothing
        Catch ex As Exception
            obj = Nothing
        Finally
            GC.Collect()
        End Try
    End Sub
End Class

Member 14179211 wrote:

I been trying this for long period.

RedPandinus wrote:

How to add 3 IF conditions to below code part ?

Private Sub btnSave_Click(sender As System.Object, e As System.EventArgs) Handles btnSave.Click
     
        If txtFullname.Text = "" Or IsNothing(txtFullname.Text) Or txtFullname.Text.Length = 0 Then
            MessageBox.Show("test", "Warning",
                            MessageBoxButtons.OK, MessageBoxIcon.Warning)
            txtFullname.Focus()
            Exit Sub
        End If
    
        If NewData Then
       
            strSQL = _
                " SELECT Count(tblContact.Fullname) AS CountFullname FROM tblContact " & _
                " WHERE Fullname = " & "'" & txtFullname.Text & "'"
            If DuplicateName(strSQL) Then
                MessageBox.Show("Test", "Warning",
                                MessageBoxButtons.OK, MessageBoxIcon.Warning)
                txtFullname.Focus()
                Exit Sub
            End If