MYSQL Query question

["Reinhart Viane" <rv@xxxxxxxx>]

Table chat_online:
session (varchar)
activity (datetime)
 
Table persons
persons_region_int(int)
 
Table regions
region_id
region_name
 
On a page i list all persons which are in the chat_online dbase and
within a certain period:
$limit_time = time() - 130; // 2 Minutes time out. 60 * 2 = 120 
$sqlchatonline = "SELECT * FROM chat_online WHERE
UNIX_TIMESTAMP(activity) >= $limit_time AND
(sessionid!='".session_id()."')";
$resultchatonline=mysql_query($sqlchatonline) or die (mysql_error());
$chatvisits = mysql_num_rows($resultchatonline);
 
while($rowchatonline = mysql_fetch_object($resultchatonline)){
   $chattersessionid=$rowchatonline->sessionid;
   //get the username, userid, mainpicid from the online chatter
   $getinfo= "select * from persons where
person_session_id='$chattersessionid'";
   $resultgetinfo = mysql_query($getinfo) or die (mysql_error());
   $rowgetinfo= mysql_fetch_array($resultgetinfo);
    echo $rowgetinfo['person_nick'];
}
 
Now i want these online chatters to be listed by person_region_int:
something like:
region A
    chatter1
    chatter2
region B
    none
region C
    chatter3
    chatter4
 
How do i do this?
 
And a second question:
I have created a menu box which lists all regions, if a option is
selected by the user, i only want to show the online chatters of the
selected region (selecting an option defines a variable $region which
holds the region_id)
Something like:
if ($region) {
$sqlchatonline = "SELECT * FROM chat_online, persons WHERE
UNIX_TIMESTAMP(chat_online.activity) >= $limit_time AND
(chat_online.sessionid!='".session_id()."' AND
(persons.persons_region_int='$region')";
}
 
This doe not give me the correct result: it shows all online chatters *
total amount of users of that region. It should be all online chatters
from that specified region
 
And a last question:
I always seem to get stuck on mysql queries when scripting. mysql.com
gives me a headache whens earching something. Does someone know a good
mysql manual site or a good mysql book?
 
Thx in advance
Reinhart
 
  _____  

Reinhart Viane 
 <mailto:rv@xxxxxxxx> rv@xxxxxxxx 
Domos || D-Studio 
Graaf Van Egmontstraat 15/3 -- B 2800 Mechelen -- tel +32 15 44 89 01 --
fax +32 15 43 25 26 


STRICTLY PERSONAL AND CONFIDENTIAL 
This message may contain confidential and proprietary material for the
sole use of the intended 
recipient.  Any review or distribution by others is strictly prohibited.
If you are not the intended 
recipient please contact the sender and delete all copies.