DB_Query usage example

<?php
/**
* DB query constructor usage example.
*
* Let we record own simple site visit statistic and we have following structures/data:
* <pre>
* CREATE TABLE `user` (
* `id` int(10) unsigned NOT NULL,
* `name` varchar(255) NOT NULL,
* PRIMARY KEY (`id`)
* );
* INSERT INTO `user` VALUES (1,'Tom');
* INSERT INTO `user` VALUES (2,'Soap');
* INSERT INTO `user` VALUES (3,'Eddy');
* INSERT INTO `user` VALUES (4,'Bacon');
*
* CREATE TABLE `page` (
* `id` int(10) unsigned NOT NULL,
* `url` varchar(255) NOT NULL,
* PRIMARY KEY (`id`)
* );
* INSERT INTO `page` VALUES (1,'/');
* INSERT INTO `page` VALUES (2,'/poker');
*
* CREATE TABLE `visit` (
* `id` int(10) unsigned NOT NULL,
* `date` datetime NOT NULL,
* `id_user` int(11) unsigned NOT NULL,
* `id_page` int(11) unsigned NOT NULL,
* `ip` int(11) unsigned NOT NULL COMMENT 'INET_NTOA() / INET_ATON()',
* PRIMARY KEY (`id`)
* );
* INSERT INTO `visit` VALUES (1,'1998-09-27 17:44:52',1,1,3232235521);
* INSERT INTO `visit` VALUES (2,'1998-09-27 17:45:54',2,1,3232235522);
* INSERT INTO `visit` VALUES (3,'1998-09-27 15:23:38',3,1,3232235523);
* INSERT INTO `visit` VALUES (4,'1998-09-27 15:25:38',4,1,3232235524);
* INSERT INTO `visit` VALUES (5,'1998-09-30 15:25:38',3,2,3232235523);
* </pre>
*
* This script must be located at site root.
* It will output:
* <pre>
* SELECT u.name,COUNT(v.id) cnt
* FROM user u
* LEFT OUTER JOIN visit v ON u.id = v.id_user
* WHERE 1 AND u.name LIKE '%a%'
* GROUP BY v.id_user
* </pre>
*
* @copyright Amiro.CMS.
* @category Example
* @package DB
* @since 5.10.0
*/
require 'ami_env.php';
// @var AMI_Response
$oResponse = AMI::getSingleton('response');
$oResponse->start();
// Let we need to get users having 'a' in their name and number of page visited.<br>
$oQuery = new DB_Query('user', 'u');
$oQuery
->addField('name', 'u')
->addExpressionField('COUNT(v.id) cnt')
->addJoinedTable('visit', 'v', 'u.id = v.id_user', 'LEFT OUTER JOIN')
->addWhereDef(
DB_Query::getSnippet('AND u.name LIKE %s')->q('%a%')
)
->addGrouping('v.id_user');
$oResponse->write($oQuery->get());
$oResponse->send();