Sort order file when sent to xml - mysql

Question

I have the following statement:
$query = "SELECT * FROM aprstrack WHERE callsignSSID = 'VE9SC-9' order by reporttime desc limit 30 ";
It works but I am feeding the results to a xml file that needs the order reversed to what is displayed.
The display looks like this:
<?xml version="1.0" ?>
- <markers>
<marker call="VE9SC-9" lat="46.1088" lng="-64.8708" datetime="2012-01-20 20:26:33" course="" Speed="28" alt="" Icon="/P" />
<marker call="VE9SC-9" lat="46.1038" lng="-64.8633" datetime="2012-01-20 20:25:23" course="" Speed="26" alt="" Icon="/P" />
<marker call="VE9SC-9" lat="46.1038" lng="-64.8625" datetime="2012-01-20 20:25:19" course="" Speed="16" alt="" Icon="/P" />
<marker call="VE9SC-9" lat="46.1037" lng="-64.862" datetime="2012-01-20 20:25:11" course="" Speed="10" alt="" Icon="/P" />
<marker call="VE9SC-9" lat="46.1035" lng="-64.8622" datetime="2012-01-20 20:25:05" course="" Speed="14" alt="" Icon="/P" />
<marker call="VE9SC-9" lat="46.0978" lng="-64.86" datetime="2012-01-20 20:24:18" course="" Speed="18" alt="" Icon="/P" />
<marker call="VE9SC-9" lat="46.0943" lng="-64.8407" datetime="2012-01-20 20:21:40" course="" Speed="40" alt="" Icon="/P" />
<marker call="VE9SC-9" lat="46.0977" lng="-64.8178" datetime="2012-01-20 20:19:08" course="" Speed="12" alt="" Icon="/P" />
</markers>
The newest being listed on the top, what I need is the oldest listed on the top.
I have tried desc & ASC but that will not work what needs to be done ? I have looked on-line and I can not find an answer.
Thanks
Stephen

Answer 1

MySQL does the ordering first and then limits the results. That is why you would get the 30 oldest results. You need to do a subquery such that ordering happens after you have pulled the 30 newest records:
$query = "SELECT * FROM (SELECT * FROM aprstrack WHERE callsignSSID = 'VE9SC-9' order by reporttime desc limit 30) ORDER BY reporttime ASC";