UpdateQuery.php

<?php
/* vim: set expandtab tabstop=4 shiftwidth=4 softtabstop=4 enc=utf8: */
/**
 * @author Alexey Zakhlestin
 * @package mysql-query-builder
 **/
/*
 MySQL Query Builder
 Copyright © 2005-2009 Alexey Zakhlestin <indeyets@gmail.com>
 Copyright © 2005-2006 Konstantin Sedov <kostya.online@gmail.com>

 This library is free software; you can redistribute it and/or
 modify it under the terms of the GNU Lesser General Public
 License as published by the Free Software Foundation; either
 version 2.1 of the License, or (at your option) any later version.

 This library 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
 Lesser General Public License for more details.

 You should have received a copy of the GNU Lesser General Public
 License along with this library; if not, write to the Free Software
 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/

/**
 * This class contains logic of "UPDATE" queries
 *
 * @package mysql-query-builder
 * @author Alexey Zakhlestin
 */
class UpdateQuery extends BasicQuery
{
 private $set_fields = null;
 private $set_values = null;
 private $up_limit = null;

 /**
 * Creates new UPDATE-query object.
 * By default, it is equivalent of "UPDATE t0, t1, t2, tN SET …", where t0-tN are tables given to this constructor
 * Be sure to specify some fields to be updated, or query will fail to be generated
 *
 * @param mixed $tables 
 */
 public function __construct($tables)
 {
 parent::__construct($tables);

 $this->set_fields = array();
 $this->set_values = array();
 }

 /**
 * magic accessor, which lets setting parts of "SET …" clause with simple "$obj->field = 'value';" statements
 *
 * @param string $key 
 * @param mixed $value 
 * @return void
 */
 public function __set($key, $value)
 {
 $this->set_fields[] = new Field($key);
 $this->set_values[] = new Parameter($value);
 $this->reset();
 }

 /**
 * sets "SET …" clause of query to the new value. Array is supposed to be in one of the following formats: 
 * 1) [field_name => value, field2 => value2, …] 
 * 2) [[field_name, value], [field2, value2], …] 
 *
 * @param array $sets 
 * @return void
 */
 public function setValues(array $sets)
 {
 $this->set_fields = array();
 $this->set_values = array();

 if (count($sets) == 0)
 return;

 foreach ($sets as $set => $value) {
 if (is_array($value)) {
 // nested arrays. $value[0] is Field, $value[1] is Parameter
 if (is_string($value[0]))
 $value[0] = new Field($value[0]);

 $this->set_fields[] = $value[0];
 $this->set_values[] = new Parameter($value[1]);
 } else {
 // key-value pairs
 $this->set_fields[] = new Field($set);
 $this->set_values[] = new Parameter($value);
 }
 }

 $this->reset();
 }

 /**
 * Sets maximum number of rows, the UPDATE query will be applied to.
 * MySQL does not allow to specify offset, so, it is just a single number
 *
 * @param integer $limit 
 * @return void
 * @throws LogicException, InvalidArgumentException
 */
 public function setLimit($limit)
 {
 if (count($this->from) != 1) {
 throw new LogicException("setLimit is allowed only in single-table update queries");
 }

 if (!is_numeric($limit) or $limit < 1)
 throw new InvalidArgumentException('setLimit takes as single numeric greater than zero');

 $this->up_limit = (string)$limit;
 }

 /**
 * wrapper around BasicQuery::setOrderBy, which additionally checks if it is allowed, to apply order to the query. 
 * it is allowed only for single-table queries
 *
 * @param array $orderlist 
 * @param array $orderdirectionlist 
 * @return void
 * @throws LogicException
 */
 public function setOrderby(array $orderlist, array $orderdirectionlist = array())
 {
 if (count($this->from) != 1) {
 throw new LogicException("setOrderby is allowed only in single-table update queries");
 }

 parent::setOrderby($orderlist, $orderdirectionlist);
 }

 protected function getSql(array &$parameters)
 {
 if (null === $this->set_fields)
 throw new LogicException("Nothing is specified to be set. Can't produce valid MySQL query");

 return $this->getUpdate($parameters).
 $this->getSet($parameters).
 $this->getWhere($parameters).
 $this->getOrderby($parameters).
 $this->getLimit();
 }

 protected function getLimit()
 {
 return (null == $this->up_limit) ? '' : ' LIMIT '.$this->up_limit;
 }

 private function getUpdate(&$parameters)
 {
 $sql = 'UPDATE ';

 for ($i = 0; $i < count($this->from); $i++) {
 if ($i > 0)
 $sql .= ', ';
 $sql .= $this->from[$i]->__toString().' AS `t'.$i.'`';
 }

 return $sql;
 }

 protected function getSet(&$parameters)
 {
 if (null === $this->set_fields or 0 == count($this->set_fields))
 throw new LogicException("Empty update-queries are forbidden");

 $sqls = array();
 foreach ($this->set_fields as $i => $value) {
 $sqls[] = $value->getSql($parameters).' = '.$this->set_values[$i]->getSql($parameters);
 }

 return " SET ".implode(", ", $sqls);
 }
}