如何在vb.net中从数据库中选择最大值

Question

我有不同价值的数据库

number_reg

10

9

15

18

我试过

    sql = "SELECT * from table where number_reg=(SELECT max(number_reg)from table)"
    cmd = New OdbcCommand(sql, conn)
    dtreader = cmd.ExecuteReader
    If dtreader.Read Then
        textbox1.Text = dtreader.Item("number_reg") 
    Else
        textbox1.Text = "0"
    End If

但输出是10如何获得输出是18 ??