In your main.php config file, you may already have a db component set up by default.

//.. main.php
'db'=>array(
	'connectionString' => 'mysql:host=localhost;dbname=testdrive',
	'emulatePrepare' => true,
	'username' => 'root',
	'password' => 'password',
	'charset' => 'utf8',
),

This will be enabled by default. Now, if you want to enable another connection component, simply add another CDbConnection component and give it a different name.

//.. main.php
'db'=>array(
	'connectionString' => 'mysql:host=localhost;dbname=testdrive',
	'emulatePrepare' => true,
	'username' => 'root',
	'password' => 'password',
	'charset' => 'utf8',
),
'db2'=>array(
        'class'  => 'CDbConnection',
	'connectionString' => 'mysql:host=localhost;dbname=database2',
	'emulatePrepare' => true,
	'username' => 'root',
	'password' => 'password',
	'charset' => 'utf8',
),

Now, in your models you can pass the connection instance using getDbConnection()

class DbTable extends CActiveRecord
{
     public static function model($className=__CLASS__)
    {
        return parent::model($className);
    }

    public function getDbConnection()
    {
        return Yii::app()->db2; // select the connection you want
    }
//.. etc

Using this technique you can have your model classes connect to numerous databases.

Enjoy

/*

Copyright 2009  Kevin Bradwick (http://www.kevinbradwick.co.uk) 

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version. 

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.
*/

function geoRadius($lat, $lng, $rad, $kilometeres = FALSE, $out = 'OBJ')
	{
		$radius = ($kilometers) ? ($rad * 0.621371192) : $rad;

		(float)$dpmLAT = 1 / 69.1703234283616; 

		// Latitude calculation
		(float)$usrRLAT = $dpmLAT * $radius;
		(float)$latMIN = $lat - $usrRLAT;
		(float)$latMAX = $lat + $usrRLAT;

		// Longitude calculation
		(float)$mpdLON = 69.1703234283616 * cos($lat * (pi/180));
		(float)$dpmLON = 1 / $mpdLON; // degrees per mile longintude
		$usrRLON = $dpmLON * $radius;
		$lonMIN = $lng - $usrRLON;
		$lonMAX = $lng + $usrRLON;

		$output = array("lonMIN" => $lonMIN, "lonMAX" => $lonMAX, "latMIN" => $latMIN, "latMAX" => $latMAX);
		return ($out == 'OBJ') ? (object)$output : $output;
	}

Okay, so how do you use it? Well, the first two paramaters are the Latitude and Longitude of your origin. The third is the radius ammount. If you want to calculate it based on kilometers (default is in miles), enter a boolean value of TRUE for the fourth parameter. The last paramter specifices the output method, by default it will return an object, enter anything other that OBJ here will return an associative array.

So, once we’ve done that what do we have? You will then have 4 variables to use, each of them minimum and maximum values of Latitude and Longitude. This is how you could use the output of this function to query a database that contains geo data.

$radius = geoRadius(53.741690, -2.397750, 48.28032);
$sql = "SELECT * FROM `mytable` WHERE `latitude` BETWEEN {$radius->latMIN} AND {$radius->latMAX} AND `longitude` BETWEEN {$radius->lonMIN} AND {$radius->lonMAX}";

First step is to install some dependencies.

yum install automake php-devel libtool openssl-devel gcc++ gcc

Next, let’s download the latest release of libssh2 (1.2.2 at time of writing), unpack and install

# cd /tmp
# wget http://www.libssh2.org/download/libssh2-1.2.2.tar.gz
# tar -zxf libssh2-1.2.2.tar.gz
# cd libssh2-1.2.2
# ./configure
# make all install
# cd ..
# rm -rf libssh2-1.2.2

Now we need to install the PHP bindings.

# cd /usr/lib/php (for x64 systems use /usr/lib64/php)
# wget http://pecl.php.net/get/ssh2-0.11.0.tgz
# tar -zxf ssh2-0.11.0.tgz
# cd ssh2-0.11.0
# phpize && ./configure –with-ssh2 && make
# cd modules
# mv ssh2.so /usr/lib/php/modules/ssh2.so
# cd /usr/lib/php
# rm -rf ssh2-0.11.0
# rm -f ssh2-0.11.0.tgz

Update the PHP ini file and add the ssh2.so extension like this.

# vi /etc/php.ini
extension_dir = “/usr/lib/php/modules”
extension = ssh2.so

Now restart apache and everything should be installed. You can test it my looking at the out put of # php -m that will list all of the installed modules.

For these situations, I have compiled a list of timezones as an array that you can use in you projects. Either cut and paste the code below or download the file.

/**
 * Timezone List
 * Array compiled from timezone_identifiers_list() that can be used on
 * systems that do not support the function but a list of timezones is
 * needed anyway
 **/

$timezone = array(
		'Africa/Abidjan',
		'Africa/Accra',
		'Africa/Addis_Ababa',
		'Africa/Algiers',
		'Africa/Asmara',
		'Africa/Bamako',
		'Africa/Bangui',
		'Africa/Banjul',
		'Africa/Bissau',
		'Africa/Blantyre',
		'Africa/Brazzaville',
		'Africa/Bujumbura',
		'Africa/Cairo',
		'Africa/Casablanca',
		'Africa/Ceuta',
		'Africa/Conakry',
		'Africa/Dakar',
		'Africa/Dar_es_Salaam',
		'Africa/Djibouti',
		'Africa/Douala',
		'Africa/El_Aaiun',
		'Africa/Freetown',
		'Africa/Gaborone',
		'Africa/Harare',
		'Africa/Johannesburg',
		'Africa/Kampala',
		'Africa/Khartoum',
		'Africa/Kigali',
		'Africa/Kinshasa',
		'Africa/Lagos',
		'Africa/Libreville',
		'Africa/Lome',
		'Africa/Luanda',
		'Africa/Lubumbashi',
		'Africa/Lusaka',
		'Africa/Malabo',
		'Africa/Maputo',
		'Africa/Maseru',
		'Africa/Mbabane',
		'Africa/Mogadishu',
		'Africa/Monrovia',
		'Africa/Nairobi',
		'Africa/Ndjamena',
		'Africa/Niamey',
		'Africa/Nouakchott',
		'Africa/Ouagadougou',
		'Africa/Porto-Novo',
		'Africa/Sao_Tome',
		'Africa/Tripoli',
		'Africa/Tunis',
		'Africa/Windhoek',
		'America/Adak',
		'America/Anchorage',
		'America/Anguilla',
		'America/Antigua',
		'America/Araguaina',
		'America/Argentina/Buenos_Aires',
		'America/Argentina/Catamarca',
		'America/Argentina/Cordoba',
		'America/Argentina/Jujuy',
		'America/Argentina/La_Rioja',
		'America/Argentina/Mendoza',
		'America/Argentina/Rio_Gallegos',
		'America/Argentina/Salta',
		'America/Argentina/San_Juan',
		'America/Argentina/San_Luis',
		'America/Argentina/Tucuman',
		'America/Argentina/Ushuaia',
		'America/Aruba',
		'America/Asuncion',
		'America/Atikokan',
		'America/Bahia',
		'America/Barbados',
		'America/Belem',
		'America/Belize',
		'America/Blanc-Sablon',
		'America/Boa_Vista',
		'America/Bogota',
		'America/Boise',
		'America/Cambridge_Bay',
		'America/Campo_Grande',
		'America/Cancun',
		'America/Caracas',
		'America/Cayenne',
		'America/Cayman',
		'America/Chicago',
		'America/Chihuahua',
		'America/Costa_Rica',
		'America/Cuiaba',
		'America/Curacao',
		'America/Danmarkshavn',
		'America/Dawson',
		'America/Dawson_Creek',
		'America/Denver',
		'America/Detroit',
		'America/Dominica',
		'America/Edmonton',
		'America/Eirunepe',
		'America/El_Salvador',
		'America/Fortaleza',
		'America/Glace_Bay',
		'America/Godthab',
		'America/Goose_Bay',
		'America/Grand_Turk',
		'America/Grenada',
		'America/Guadeloupe',
		'America/Guatemala',
		'America/Guayaquil',
		'America/Guyana',
		'America/Halifax',
		'America/Havana',
		'America/Hermosillo',
		'America/Indiana/Indianapolis',
		'America/Indiana/Knox',
		'America/Indiana/Marengo',
		'America/Indiana/Petersburg',
		'America/Indiana/Tell_City',
		'America/Indiana/Vevay',
		'America/Indiana/Vincennes',
		'America/Indiana/Winamac',
		'America/Inuvik',
		'America/Iqaluit',
		'America/Jamaica',
		'America/Juneau',
		'America/Kentucky/Louisville',
		'America/Kentucky/Monticello',
		'America/La_Paz',
		'America/Lima',
		'America/Los_Angeles',
		'America/Maceio',
		'America/Managua',
		'America/Manaus',
		'America/Marigot',
		'America/Martinique',
		'America/Mazatlan',
		'America/Menominee',
		'America/Merida',
		'America/Mexico_City',
		'America/Miquelon',
		'America/Moncton',
		'America/Monterrey',
		'America/Montevideo',
		'America/Montreal',
		'America/Montserrat',
		'America/Nassau',
		'America/New_York',
		'America/Nipigon',
		'America/Nome',
		'America/Noronha',
		'America/North_Dakota/Center',
		'America/North_Dakota/New_Salem',
		'America/Panama',
		'America/Pangnirtung',
		'America/Paramaribo',
		'America/Phoenix',
		'America/Port-au-Prince',
		'America/Port_of_Spain',
		'America/Porto_Velho',
		'America/Puerto_Rico',
		'America/Rainy_River',
		'America/Rankin_Inlet',
		'America/Recife',
		'America/Regina',
		'America/Resolute',
		'America/Rio_Branco',
		'America/Santarem',
		'America/Santiago',
		'America/Santo_Domingo',
		'America/Sao_Paulo',
		'America/Scoresbysund',
		'America/Shiprock',
		'America/St_Barthelemy',
		'America/St_Johns',
		'America/St_Kitts',
		'America/St_Lucia',
		'America/St_Thomas',
		'America/St_Vincent',
		'America/Swift_Current',
		'America/Tegucigalpa',
		'America/Thule',
		'America/Thunder_Bay',
		'America/Tijuana',
		'America/Toronto',
		'America/Tortola',
		'America/Vancouver',
		'America/Whitehorse',
		'America/Winnipeg',
		'America/Yakutat',
		'America/Yellowknife',
		'Antarctica/Casey',
		'Antarctica/Davis',
		'Antarctica/DumontDUrville',
		'Antarctica/Mawson',
		'Antarctica/McMurdo',
		'Antarctica/Palmer',
		'Antarctica/Rothera',
		'Antarctica/South_Pole',
		'Antarctica/Syowa',
		'Antarctica/Vostok',
		'Arctic/Longyearbyen',
		'Asia/Aden',
		'Asia/Almaty',
		'Asia/Amman',
		'Asia/Anadyr',
		'Asia/Aqtau',
		'Asia/Aqtobe',
		'Asia/Ashgabat',
		'Asia/Baghdad',
		'Asia/Bahrain',
		'Asia/Baku',
		'Asia/Bangkok',
		'Asia/Beirut',
		'Asia/Bishkek',
		'Asia/Brunei',
		'Asia/Choibalsan',
		'Asia/Chongqing',
		'Asia/Colombo',
		'Asia/Damascus',
		'Asia/Dhaka',
		'Asia/Dili',
		'Asia/Dubai',
		'Asia/Dushanbe',
		'Asia/Gaza',
		'Asia/Harbin',
		'Asia/Ho_Chi_Minh',
		'Asia/Hong_Kong',
		'Asia/Hovd',
		'Asia/Irkutsk',
		'Asia/Jakarta',
		'Asia/Jayapura',
		'Asia/Jerusalem',
		'Asia/Kabul',
		'Asia/Kamchatka',
		'Asia/Karachi',
		'Asia/Kashgar',
		'Asia/Kathmandu',
		'Asia/Kolkata',
		'Asia/Krasnoyarsk',
		'Asia/Kuala_Lumpur',
		'Asia/Kuching',
		'Asia/Kuwait',
		'Asia/Macau',
		'Asia/Magadan',
		'Asia/Makassar',
		'Asia/Manila',
		'Asia/Muscat',
		'Asia/Nicosia',
		'Asia/Novosibirsk',
		'Asia/Omsk',
		'Asia/Oral',
		'Asia/Phnom_Penh',
		'Asia/Pontianak',
		'Asia/Pyongyang',
		'Asia/Qatar',
		'Asia/Qyzylorda',
		'Asia/Rangoon',
		'Asia/Riyadh',
		'Asia/Sakhalin',
		'Asia/Samarkand',
		'Asia/Seoul',
		'Asia/Shanghai',
		'Asia/Singapore',
		'Asia/Taipei',
		'Asia/Tashkent',
		'Asia/Tbilisi',
		'Asia/Tehran',
		'Asia/Thimphu',
		'Asia/Tokyo',
		'Asia/Ulaanbaatar',
		'Asia/Urumqi',
		'Asia/Vientiane',
		'Asia/Vladivostok',
		'Asia/Yakutsk',
		'Asia/Yekaterinburg',
		'Asia/Yerevan',
		'Atlantic/Azores',
		'Atlantic/Bermuda',
		'Atlantic/Canary',
		'Atlantic/Cape_Verde',
		'Atlantic/Faroe',
		'Atlantic/Madeira',
		'Atlantic/Reykjavik',
		'Atlantic/South_Georgia',
		'Atlantic/St_Helena',
		'Atlantic/Stanley',
		'Australia/Adelaide',
		'Australia/Brisbane',
		'Australia/Broken_Hill',
		'Australia/Currie',
		'Australia/Darwin',
		'Australia/Eucla',
		'Australia/Hobart',
		'Australia/Lindeman',
		'Australia/Lord_Howe',
		'Australia/Melbourne',
		'Australia/Perth',
		'Australia/Sydney',
		'Europe/Amsterdam',
		'Europe/Andorra',
		'Europe/Athens',
		'Europe/Belgrade',
		'Europe/Berlin',
		'Europe/Bratislava',
		'Europe/Brussels',
		'Europe/Bucharest',
		'Europe/Budapest',
		'Europe/Chisinau',
		'Europe/Copenhagen',
		'Europe/Dublin',
		'Europe/Gibraltar',
		'Europe/Guernsey',
		'Europe/Helsinki',
		'Europe/Isle_of_Man',
		'Europe/Istanbul',
		'Europe/Jersey',
		'Europe/Kaliningrad',
		'Europe/Kiev',
		'Europe/Lisbon',
		'Europe/Ljubljana',
		'Europe/London',
		'Europe/Luxembourg',
		'Europe/Madrid',
		'Europe/Malta',
		'Europe/Mariehamn',
		'Europe/Minsk',
		'Europe/Monaco',
		'Europe/Moscow',
		'Europe/Oslo',
		'Europe/Paris',
		'Europe/Podgorica',
		'Europe/Prague',
		'Europe/Riga',
		'Europe/Rome',
		'Europe/Samara',
		'Europe/San_Marino',
		'Europe/Sarajevo',
		'Europe/Simferopol',
		'Europe/Skopje',
		'Europe/Sofia',
		'Europe/Stockholm',
		'Europe/Tallinn',
		'Europe/Tirane',
		'Europe/Uzhgorod',
		'Europe/Vaduz',
		'Europe/Vatican',
		'Europe/Vienna',
		'Europe/Vilnius',
		'Europe/Volgograd',
		'Europe/Warsaw',
		'Europe/Zagreb',
		'Europe/Zaporozhye',
		'Europe/Zurich',
		'Indian/Antananarivo',
		'Indian/Chagos',
		'Indian/Christmas',
		'Indian/Cocos',
		'Indian/Comoro',
		'Indian/Kerguelen',
		'Indian/Mahe',
		'Indian/Maldives',
		'Indian/Mauritius',
		'Indian/Mayotte',
		'Indian/Reunion',
		'Pacific/Apia',
		'Pacific/Auckland',
		'Pacific/Chatham',
		'Pacific/Easter',
		'Pacific/Efate',
		'Pacific/Enderbury',
		'Pacific/Fakaofo',
		'Pacific/Fiji',
		'Pacific/Funafuti',
		'Pacific/Galapagos',
		'Pacific/Gambier',
		'Pacific/Guadalcanal',
		'Pacific/Guam',
		'Pacific/Honolulu',
		'Pacific/Johnston',
		'Pacific/Kiritimati',
		'Pacific/Kosrae',
		'Pacific/Kwajalein',
		'Pacific/Majuro',
		'Pacific/Marquesas',
		'Pacific/Midway',
		'Pacific/Nauru',
		'Pacific/Niue',
		'Pacific/Norfolk',
		'Pacific/Noumea',
		'Pacific/Pago_Pago',
		'Pacific/Palau',
		'Pacific/Pitcairn',
		'Pacific/Ponape',
		'Pacific/Port_Moresby',
		'Pacific/Rarotonga',
		'Pacific/Saipan',
		'Pacific/Tahiti',
		'Pacific/Tarawa',
		'Pacific/Tongatapu',
		'Pacific/Truk',
		'Pacific/Wake',
		'Pacific/Wallis',
		'UTC');