Dim SQLcmd As New OleDb.OleDbCommand
Dim sql, condition1, condition2, condition3 As String
Private Sub TextBox1_TextChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles TextBox1.TextChanged
If TextBox1.Text = "" Then
condition1 = "(TRUE)"
Else
condition1 = "(Field1=@arg1)"
SQLcmd.Parameters.AddWithValue("arg1", Textbox1.Text)
End If
End Sub
Private Sub TextBox2_TextChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles TextBox1.TextChanged
If TextBox1.Text = "" Then
condition2 = "(TRUE)"
Else
condition2 = "(Field2=@arg2)"
SQLcmd.Parameters.AddWithValue("arg2", Textbox2.Text)
End If
End Sub
Private Sub TextBox3_TextChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles TextBox1.TextChanged
If TextBox1.Text = "" Then
condition3 = "(TRUE)"
Else
condition3 = "(Field3=@arg3)"
SQLcmd.Parameters.AddWithValue("arg3", Textbox3.Text)
End If
End Sub
Private Sub btnSumbit_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnSubmit.Click
SQLcmd.CommandText = "SELECT * FROM MyTable WHERE " _
& condition1 & " AND " _
& condition2 & " AND " _
& condition3 & ";"
' Submit your sql
' SAFE from injections!
End Sub