VBScript 每 30 秒回显一次

VBScript echo every 30 seconds

以下代码每次迭代都会写入屏幕。根据我对 the DateDiff documentation 的理解,它应该只每 30 秒写入一次。我做错了什么?

lasttime = Now
Do While Not data.eof
    'looping through database records
    if DateDiff(s,lasttime,Now) >= 30 Then
        lasttime = Now
        WScript.Echo "It's been 30 seconds..."
    End if
Loop

更改此行:

if DateDiff(s,lasttime,Now) >= 30 Then

为此(注意 "s" 周围的引号)

if DateDiff("s",lasttime,Now) >= 30 Then