Showing all fields in listbox from database, vb.net - sql

Question

I'm trying to make a list box to show all the fields of a particular table in an Access database. I have a few tables, and the idea would be to have each table loaded by a different button (and the items in the box cleared). One trick is that tables aren't all the same size. How do I get all the fields to show up for each table. What I have now is only showing one field:
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim connString As String = "Provider=Microsoft.ACE.OLEDB.12.0;data source='C:\dummy_data.accdb';"
Dim conn As New OleDbConnection(connString)
Dim sql As String = "SELECT * FROM Customers"
Dim cmd As New OleDbCommand(sql, conn)
conn.Open()
Dim reader As OleDbDataReader = cmd.ExecuteReader()
ClientList.Items.Clear()
While reader.Read()
ClientList.Items.Add(reader(0).ToString())
End While
reader.Close()
conn.Close()
End Sub

Answer 1

If you are not averse to using a DataGridView instead of a ListView, you could do it this way:
Dim connString As String = "Provider=Microsoft.Jet.OLEDB.4.0;data source='PathToMyDatabase';"
Dim sql As String = "SELECT * FROM Tメイン;"
Dim dt As DataTable
With New OleDbDataAdapter(sql, connString)
Dim ds As New DataSet()
.Fill(ds)
dt = ds.Tables(0)
End With
Me.DataGridView1.DataSource = dt
I do not have 'ACE.OLEDB' on my computer, so had to use the JET provider instead, but it should work the same way.
I should add that you can use this method to retrieve the data from the DB, but there is no easy way as far as I understand to bind a DataTable to a ListView (see this MSDN question for example) and you would have to loop through the columns in your DataTable first and add the column headers to your ListView and then loop through the rows and add the data.
UPDATE:
To answer your questiona s to how to export data from the DataGridView I remembered that I wrote code to do that a little while back.
Private Function ExportToExcelFile(ByVal FileName As String) As Boolean
With New Excel.Application
With .Workbooks.Add()
For Each sheet As Worksheet In .Worksheets
If sheet.Index > 1 Then
Call sheet.Delete()
End If
Next
With CType(.Worksheets(1), Worksheet).Range("A1")
For Each column As DataGridViewColumn In Me.dgvData.Columns
.Offset(0, column.Index).Value = column.HeaderText
For Each row As DataGridViewRow In Me.dgvData.Rows
.Offset(row.Index + 1, column.Index).Value = row.Cells(column.Index).Value
Next
Next
End With
Call .SaveAs(FileName)
End With
Call .Quit()
End With
End Function
I hope this will help to get you started.

Answer 2

Using a Listview control, the following code should do the trick. For simplicity I defined only 4 customer fields - you will need to define them according to your table field defintions:
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
ClientList.View = View.Details
ClientList.FullRowSelect = True
ClientList.Columns.Add("ID", 120)
ClientList.Columns.Add("Name", 120)
ClientList.Columns.Add("Address", 140)
ClientList.Columns.Add("Email", 100)
Dim connString As String = "Provider=Microsoft.ACE.OLEDB.12.0;data source=C:\dummy_data.accdb;"
ClientList.Items.Clear()
Using conn As New Data.OleDb.OleDbConnection(connString)
conn.Open()
Dim sql As String = "SELECT * FROM Customers"
Using cmd As New Data.OleDb.OleDbCommand(sql, conn)
Dim lvi As ListViewItem
Using oRDR As Data.OleDb.OleDbDataReader = cmd.ExecuteReader
While oRDR.Read()
lvi = ClientList.Items.Add(oRDR.GetValue(0).ToString)
For i = 1 To oRDR.FieldCount - 1
lvi.SubItems.Add(oRDR.GetValue(i).ToString)
Next
End While
End Using
End Using
conn.Close()
End Using
End Sub