Ricerca con ADO

'Ricerca con ADO


Imports System.Data.OleDb
Imports System.Windows.Forms

'Public Class Form1

' Inherits System.Windows.Forms.Form




Private Sub Trova_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Trova.Click

'*************

' connessione

'*************

Dim ConnString As String = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\Prova\1\ado\EsempioAdo\bin\archivi.mdb"
'Dichiaro la stringa di connessione

Dim cn As New OleDbConnection(ConnString) 'Dichiaro la nuova connessione

cn.Open()


Dim testotxt As String = txtTrova.Text
txtOut.Text = ""
txtTrova.Text = ""
txtTrova.Focus()

If cn.State = ConnectionState.Open Then

Dim sql As String = "select * from domanda where IdMatricola=?"
Dim cmd As New OleDbCommand(sql, cn)
cmd.Parameters.Add("idMatricola", testotxt)
Dim dr As OleDbDataReader = cmd.ExecuteReader

Do While dr.Read
txtOut.AppendText(dr.Item("Idmatricola") & " - " & dr.Item("Nominativo"))

Loop
If txtOut.Text = "" Then
MessageBox.Show("Nessun autore corrisponde a questo indice", "Attenzione!", MessageBoxButtons.OK, MessageBoxIcon.Exclamation)
End If
dr.Close()

Else
MessageBox.Show("Il db non e' ancora connesso", "Attenzione", MessageBoxButtons.OK, MessageBoxIcon.Exclamation)
End If

End Sub
End Class