主题：Select 语句如何判断表中数据是否存在？

Dim cnt As Integer
Dim cmd As New SQLCommand
cmd.CommandText = "Select Count(*) From {订单} Where 产品 = 'PD01'"
cnt = cmd.ExecuteNonQuery()
If cnt >0 Then

     MessageBox.show("存在PD01的订单")
End If