Here's the table for the database:

CREATE TABLE IF NOT EXISTS `meetme` (
  `confno` int(5) NOT NULL default '0',
  `username` varchar(64) default NULL,
  `domain` varchar(128) default NULL,
  `pin` varchar(20) default NULL,
  `adminpin` varchar(20) default NULL,
  `members` int(4) NOT NULL default '0',
  `starttime` datetime default NULL,
  `endtime` datetime default NULL,
  `musiconhold` tinyint(1) NOT NULL default '1',
  `record2` tinyint(1) default NULL,
  `unique` varchar(10) NOT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8;

Here's my extension for conferences that are schedule:
_3XXXXX => { Answer();
Set(CHANNEL(musicclass)=default2); Wait(2);
CallTime="${STRFTIME(${EPOCH},,%F %T)}";
NoOp(Call time ${CallTime});
MYSQL(Connect connid localhost asterisk DATABASEPASS asterisk);
MYSQL(Query resultid ${connid} SELECT confno from asterisk.meetme where `confno`=${EXTEN:1} AND `starttime` <= "${CallTime}" AND `endtime` >= "${CallTime}";);
MYSQL(Fetch fetchid ${resultid} stuff);
MYSQL(Query resultid ${connid} SELECT `record2`,`unique`,`pin` from asterisk.meetme where `confno`=${EXTEN:1} AND `starttime` <= "${CallTime}" AND `endtime` >= "${CallTime}";);
MYSQL(Fetch fetchrow ${resultid} record2 unique2 pin);
MYSQL(Clear ${resultid});
MYSQL(Disconnect ${connid});
Set(GLOBAL(FILEPATH)=/var/www/darkvoip/html/conf-record);
Set(GLOBAL(MEETME_RECORDINGFILE)=${FILEPATH}/${stuff}-${unique2});
if (${stuff} = ${EXTEN:1}) //Does the conference ID you got from the database match the extension?
{
        NoOp(Start time: ${starttime} End time: ${endtime});
        if (${record2}=1) //If record2 is set to 1 in the database, that means to record...
        {
	        if (${pin}) //If there is a pin in the database, authenticate as app_meetme won't.
        		{
        	        Authenticate(${pin});
	                }
        Playback(this-call-may-be-monitored-or-recorded);
        NoOp(File: ${MEETME_RECORDINGFILE});
        MeetMe(${EXTEN:1},rMcCsd);
	Hangup();
        }
        else{
                 if (${pin}) //If there is a pin in the database, authenticate as app_meetme won't.
                         {
        	         Authenticate(${pin});
        	         }
        MeetMe(${EXTEN:1},McCsd,); //It isn't completely necessary to do it this way if you're not recording, but might as well make all of the code similar
	Hangup();
	}
}
else{
Playback(invalidconfyo);
Hangup();
}