/QuickApps/Cake/Model/Datasource/DboSource.php

<?php
/**
 * Dbo Source
 *
 * PHP 5
 *
 * CakePHP(tm) : Rapid Development Framework (http://cakephp.org)
 * Copyright 2005-2012, Cake Software Foundation, Inc. (http://cakefoundation.org)
 *
 * Licensed under The MIT License
 * Redistributions of files must retain the above copyright notice.
 *
 * @copyright     Copyright 2005-2012, Cake Software Foundation, Inc. (http://cakefoundation.org)
 * @link          http://cakephp.org CakePHP(tm) Project
 * @package       Cake.Model.Datasource
 * @since         CakePHP(tm) v 0.10.0.1076
 * @license       MIT License (http://www.opensource.org/licenses/mit-license.php)
 */

App::uses('DataSource', 'Model/Datasource');
App::uses('String', 'Utility');
App::uses('View', 'View');

/**
 * DboSource
 *
 * Creates DBO-descendant objects from a given db connection configuration
 *
 * @package       Cake.Model.Datasource
 */
class DboSource extends DataSource {

/**
 * Description string for this Database Data Source.
 *
 * @var string
 */
	public $description = "Database Data Source";

/**
 * index definition, standard cake, primary, index, unique
 *
 * @var array
 */
	public $index = array('PRI' => 'primary', 'MUL' => 'index', 'UNI' => 'unique');

/**
 * Database keyword used to assign aliases to identifiers.
 *
 * @var string
 */
	public $alias = 'AS ';

/**
 * Caches result from query parsing operations.  Cached results for both DboSource::name() and
 * DboSource::conditions() will be stored here.  Method caching uses `crc32()` which is
 * fast but can collisions more easily than other hashing algorithms.  If you have problems
 * with collisions, set DboSource::$cacheMethods to false.
 *
 * @var array
 */
	public static $methodCache = array();

/**
 * Whether or not to cache the results of DboSource::name() and DboSource::conditions()
 * into the memory cache.  Set to false to disable the use of the memory cache.
 *
 * @var boolean.
 */
	public $cacheMethods = true;

/**
 * Flag to support nested transactions. If it is set to false, you will be able to use
 * the transaction methods (begin/commit/rollback), but just the global transaction will
 * be executed.
 *
 * @var boolean
 */
	public $useNestedTransactions = false;

/**
 * Print full query debug info?
 *
 * @var boolean
 */
	public $fullDebug = false;

/**
 * String to hold how many rows were affected by the last SQL operation.
 *
 * @var string
 */
	public $affected = null;

/**
 * Number of rows in current resultset
 *
 * @var integer
 */
	public $numRows = null;

/**
 * Time the last query took
 *
 * @var integer
 */
	public $took = null;

/**
 * Result
 *
 * @var array
 */
	protected $_result = null;

/**
 * Queries count.
 *
 * @var integer
 */
	protected $_queriesCnt = 0;

/**
 * Total duration of all queries.
 *
 * @var integer
 */
	protected $_queriesTime = null;

/**
 * Log of queries executed by this DataSource
 *
 * @var array
 */
	protected $_queriesLog = array();

/**
 * Maximum number of items in query log
 *
 * This is to prevent query log taking over too much memory.
 *
 * @var integer Maximum number of queries in the queries log.
 */
	protected $_queriesLogMax = 200;

/**
 * Caches serialized results of executed queries
 *
 * @var array Cache of results from executed sql queries.
 */
	protected $_queryCache = array();

/**
 * A reference to the physical connection of this DataSource
 *
 * @var array
 */
	protected $_connection = null;

/**
 * The DataSource configuration key name
 *
 * @var string
 */
	public $configKeyName = null;

/**
 * The starting character that this DataSource uses for quoted identifiers.
 *
 * @var string
 */
	public $startQuote = null;

/**
 * The ending character that this DataSource uses for quoted identifiers.
 *
 * @var string
 */
	public $endQuote = null;

/**
 * The set of valid SQL operations usable in a WHERE statement
 *
 * @var array
 */
	protected $_sqlOps = array('like', 'ilike', 'or', 'not', 'in', 'between', 'regexp', 'similar to');

/**
 * Indicates the level of nested transactions
 *
 * @var integer
 */
	protected $_transactionNesting = 0;

/**
 * Default fields that are used by the DBO
 *
 * @var array
 */
	protected $_queryDefaults = array(
		'conditions' => array(),
		'fields' => null,
		'table' => null,
		'alias' => null,
		'order' => null,
		'limit' => null,
		'joins' => array(),
		'group' => null,
		'offset' => null
	);

/**
 * Separator string for virtualField composition
 *
 * @var string
 */
	public $virtualFieldSeparator = '__';

/**
 * List of table engine specific parameters used on table creating
 *
 * @var array
 */
	public $tableParameters = array();

/**
 * List of engine specific additional field parameters used on table creating
 *
 * @var array
 */
	public $fieldParameters = array();

/**
 * Indicates whether there was a change on the cached results on the methods of this class
 * This will be used for storing in a more persistent cache
 *
 * @var boolean
 */
	protected $_methodCacheChange = false;

/**
 * Constructor
 *
 * @param array $config Array of configuration information for the Datasource.
 * @param boolean $autoConnect Whether or not the datasource should automatically connect.
 * @throws MissingConnectionException when a connection cannot be made.
 */
	public function __construct($config = null, $autoConnect = true) {
		if (!isset($config['prefix'])) {
			$config['prefix'] = '';
		}
		parent::__construct($config);
		$this->fullDebug = Configure::read('debug') > 1;
		if (!$this->enabled()) {
			throw new MissingConnectionException(array(
				'class' => get_class($this)
			));
		}
		if ($autoConnect) {
			$this->connect();
		}
	}

/**
 * Reconnects to database server with optional new settings
 *
 * @param array $config An array defining the new configuration settings
 * @return boolean True on success, false on failure
 */
	public function reconnect($config = array()) {
		$this->disconnect();
		$this->setConfig($config);
		$this->_sources = null;

		return $this->connect();
	}

/**
 * Disconnects from database.
 *
 * @return boolean True if the database could be disconnected, else false
 */
	public function disconnect() {
		if ($this->_result instanceof PDOStatement) {
			$this->_result->closeCursor();
		}
		unset($this->_connection);
		$this->connected = false;
		return true;
	}

/**
 * Get the underlying connection object.
 *
 * @return PDO
 */
	public function getConnection() {
		return $this->_connection;
	}

/**
 * Gets the version string of the database server
 *
 * @return string The database version
 */
	public function getVersion() {
		return $this->_connection->getAttribute(PDO::ATTR_SERVER_VERSION);
	}

/**
 * Returns a quoted and escaped string of $data for use in an SQL statement.
 *
 * @param string $data String to be prepared for use in an SQL statement
 * @param string $column The column into which this data will be inserted
 * @return string Quoted and escaped data
 */
	public function value($data, $column = null) {
		if (is_array($data) && !empty($data)) {
			return array_map(
				array(&$this, 'value'),
				$data, array_fill(0, count($data), $column)
			);
		} elseif (is_object($data) && isset($data->type, $data->value)) {
			if ($data->type == 'identifier') {
				return $this->name($data->value);
			} elseif ($data->type == 'expression') {
				return $data->value;
			}
		} elseif (in_array($data, array('{$__cakeID__$}', '{$__cakeForeignKey__$}'), true)) {
			return $data;
		}

		if ($data === null || (is_array($data) && empty($data))) {
			return 'NULL';
		}

		if (empty($column)) {
			$column = $this->introspectType($data);
		}

		switch ($column) {
			case 'binary':
				return $this->_connection->quote($data, PDO::PARAM_LOB);
			break;
			case 'boolean':
				return $this->_connection->quote($this->boolean($data, true), PDO::PARAM_BOOL);
			break;
			case 'string':
			case 'text':
				return $this->_connection->quote($data, PDO::PARAM_STR);
			default:
				if ($data === '') {
					return 'NULL';
				}
				if (is_float($data)) {
					return str_replace(',', '.', strval($data));
				}
				if ((is_int($data) || $data === '0') || (
					is_numeric($data) && strpos($data, ',') === false &&
					$data[0] != '0' && strpos($data, 'e') === false)
				) {
					return $data;
				}
				return $this->_connection->quote($data);
			break;
		}
	}

/**
 * Returns an object to represent a database identifier in a query. Expression objects
 * are not sanitized or escaped.
 *
 * @param string $identifier A SQL expression to be used as an identifier
 * @return stdClass An object representing a database identifier to be used in a query
 */
	public function identifier($identifier) {
		$obj = new stdClass();
		$obj->type = 'identifier';
		$obj->value = $identifier;
		return $obj;
	}

/**
 * Returns an object to represent a database expression in a query.  Expression objects
 * are not sanitized or escaped.
 *
 * @param string $expression An arbitrary SQL expression to be inserted into a query.
 * @return stdClass An object representing a database expression to be used in a query
 */
	public function expression($expression) {
		$obj = new stdClass();
		$obj->type = 'expression';
		$obj->value = $expression;
		return $obj;
	}

/**
 * Executes given SQL statement.
 *
 * @param string $sql SQL statement
 * @param array $params Additional options for the query.
 * @return boolean
 */
	public function rawQuery($sql, $params = array()) {
		$this->took = $this->numRows = false;
		return $this->execute($sql, $params);
	}

/**
 * Queries the database with given SQL statement, and obtains some metadata about the result
 * (rows affected, timing, any errors, number of rows in resultset). The query is also logged.
 * If Configure::read('debug') is set, the log is shown all the time, else it is only shown on errors.
 *
 * ### Options
 *
 * - log - Whether or not the query should be logged to the memory log.
 *
 * @param string $sql SQL statement
 * @param array $options
 * @param array $params values to be bound to the query
 * @return mixed Resource or object representing the result set, or false on failure
 */
	public function execute($sql, $options = array(), $params = array()) {
		$options += array('log' => $this->fullDebug);

		$t = microtime(true);
		$this->_result = $this->_execute($sql, $params);

		if ($options['log']) {
			$this->took = round((microtime(true) - $t) * 1000, 0);
			$this->numRows = $this->affected = $this->lastAffected();
			$this->logQuery($sql, $params);
		}

		return $this->_result;
	}

/**
 * Executes given SQL statement.
 *
 * @param string $sql SQL statement
 * @param array $params list of params to be bound to query
 * @param array $prepareOptions Options to be used in the prepare statement
 * @return mixed PDOStatement if query executes with no problem, true as the result of a successful, false on error
 * query returning no rows, such as a CREATE statement, false otherwise
 * @throws PDOException
 */
	protected function _execute($sql, $params = array(), $prepareOptions = array()) {
		$sql = trim($sql);
		if (preg_match('/^(?:CREATE|ALTER|DROP)/i', $sql)) {
			$statements = array_filter(explode(';', $sql));
			if (count($statements) > 1) {
				$result = array_map(array($this, '_execute'), $statements);
				return array_search(false, $result) === false;
			}
		}

		try {
			$query = $this->_connection->prepare($sql, $prepareOptions);
			$query->setFetchMode(PDO::FETCH_LAZY);
			if (!$query->execute($params)) {
				$this->_results = $query;
				$query->closeCursor();
				return false;
			}
			if (!$query->columnCount()) {
				$query->closeCursor();
				if (!$query->rowCount()) {
					return true;
				}
			}
			return $query;
		} catch (PDOException $e) {
			if (isset($query->queryString)) {
				$e->queryString = $query->queryString;
			} else {
				$e->queryString = $sql;
			}
			throw $e;
		}
	}

/**
 * Returns a formatted error message from previous database operation.
 *
 * @param PDOStatement $query the query to extract the error from if any
 * @return string Error message with error number
 */
	public function lastError(PDOStatement $query = null) {
		if ($query) {
			$error = $query->errorInfo();
		} else {
			$error = $this->_connection->errorInfo();
		}
		if (empty($error[2])) {
			return null;
		}
		return $error[1] . ': ' . $error[2];
	}

/**
 * Returns number of affected rows in previous database operation. If no previous operation exists,
 * this returns false.
 *
 * @param mixed $source
 * @return integer Number of affected rows
 */
	public function lastAffected($source = null) {
		if ($this->hasResult()) {
			return $this->_result->rowCount();
		}
		return 0;
	}

/**
 * Returns number of rows in previous resultset. If no previous resultset exists,
 * this returns false.
 *
 * @param mixed $source Not used
 * @return integer Number of rows in resultset
 */
	public function lastNumRows($source = null) {
		return $this->lastAffected();
	}

/**
 * DataSource Query abstraction
 *
 * @return resource Result resource identifier.
 */
	public function query() {
		$args	  = func_get_args();
		$fields	  = null;
		$order	  = null;
		$limit	  = null;
		$page	  = null;
		$recursive = null;

		if (count($args) === 1) {
			return $this->fetchAll($args[0]);
		} elseif (count($args) > 1 && (strpos($args[0], 'findBy') === 0 || strpos($args[0], 'findAllBy') === 0)) {
			$params = $args[1];

			if (substr($args[0], 0, 6) === 'findBy') {
				$all = false;
				$field = Inflector::underscore(substr($args[0], 6));
			} else {
				$all = true;
				$field = Inflector::underscore(substr($args[0], 9));
			}

			$or = (strpos($field, '_or_') !== false);
			if ($or) {
				$field = explode('_or_', $field);
			} else {
				$field = explode('_and_', $field);
			}
			$off = count($field) - 1;

			if (isset($params[1 + $off])) {
				$fields = $params[1 + $off];
			}

			if (isset($params[2 + $off])) {
				$order = $params[2 + $off];
			}

			if (!array_key_exists(0, $params)) {
				return false;
			}

			$c = 0;
			$conditions = array();

			foreach ($field as $f) {
				$conditions[$args[2]->alias . '.' . $f] = $params[$c++];
			}

			if ($or) {
				$conditions = array('OR' => $conditions);
			}

			if ($all) {
				if (isset($params[3 + $off])) {
					$limit = $params[3 + $off];
				}

				if (isset($params[4 + $off])) {
					$page = $params[4 + $off];
				}

				if (isset($params[5 + $off])) {
					$recursive = $params[5 + $off];
				}
				return $args[2]->find('all', compact('conditions', 'fields', 'order', 'limit', 'page', 'recursive'));
			} else {
				if (isset($params[3 + $off])) {
					$recursive = $params[3 + $off];
				}
				return $args[2]->find('first', compact('conditions', 'fields', 'order', 'recursive'));
			}
		} else {
			if (isset($args[1]) && $args[1] === true) {
				return $this->fetchAll($args[0], true);
			} elseif (isset($args[1]) && !is_array($args[1]) ) {
				return $this->fetchAll($args[0], false);
			} elseif (isset($args[1]) && is_array($args[1])) {
				if (isset($args[2])) {
					$cache = $args[2];
				} else {
					$cache = true;
				}
				return $this->fetchAll($args[0], $args[1], array('cache' => $cache));
			}
		}
	}

/**
 * Returns a row from current resultset as an array
 *
 * @param string $sql Some SQL to be executed.
 * @return array The fetched row as an array
 */
	public function fetchRow($sql = null) {
		if (is_string($sql) && strlen($sql) > 5 && !$this->execute($sql)) {
			return null;
		}

		if ($this->hasResult()) {
			$this->resultSet($this->_result);
			$resultRow = $this->fetchResult();
			if (isset($resultRow[0])) {
				$this->fetchVirtualField($resultRow);
			}
			return $resultRow;
		} else {
			return null;
		}
	}

/**
 * Returns an array of all result rows for a given SQL query.
 * Returns false if no rows matched.
 *
 *
 * ### Options
 *
 * - `cache` - Returns the cached version of the query, if exists and stores the result in cache.
 *   This is a non-persistent cache, and only lasts for a single request. This option
 *   defaults to true. If you are directly calling this method, you can disable caching
 *   by setting $options to `false`
 *
 * @param string $sql SQL statement
 * @param array $params parameters to be bound as values for the SQL statement
 * @param array $options additional options for the query.
 * @return array Array of resultset rows, or false if no rows matched
 */
	public function fetchAll($sql, $params = array(), $options = array()) {
		if (is_string($options)) {
			$options = array('modelName' => $options);
		}
		if (is_bool($params)) {
			$options['cache'] = $params;
			$params = array();
		}
		$options += array('cache' => true);
		$cache = $options['cache'];
		if ($cache && ($cached = $this->getQueryCache($sql, $params)) !== false) {
			return $cached;
		}
		if ($result = $this->execute($sql, array(), $params)) {
			$out = array();

			if ($this->hasResult()) {
				$first = $this->fetchRow();
				if ($first != null) {
					$out[] = $first;
				}
				while ($item = $this->fetchResult()) {
					if (isset($item[0])) {
						$this->fetchVirtualField($item);
					}
					$out[] = $item;
				}
			}

			if (!is_bool($result) && $cache) {
				$this->_writeQueryCache($sql, $out, $params);
			}

			if (empty($out) && is_bool($this->_result)) {
				return $this->_result;
			}
			return $out;
		}
		return false;
	}

/**
 * Fetches the next row from the current result set
 *
 * @return boolean
 */
	public function fetchResult() {
		return false;
	}

/**
 * Modifies $result array to place virtual fields in model entry where they belongs to
 *
 * @param array $result Reference to the fetched row
 * @return void
 */
	public function fetchVirtualField(&$result) {
		if (isset($result[0]) && is_array($result[0])) {
			foreach ($result[0] as $field => $value) {
				if (strpos($field, $this->virtualFieldSeparator) === false) {
					continue;
				}
				list($alias, $virtual) = explode($this->virtualFieldSeparator, $field);

				if (!ClassRegistry::isKeySet($alias)) {
					return;
				}
				$model = ClassRegistry::getObject($alias);
				if ($model->isVirtualField($virtual)) {
					$result[$alias][$virtual] = $value;
					unset($result[0][$field]);
				}
			}
			if (empty($result[0])) {
				unset($result[0]);
			}
		}
	}

/**
 * Returns a single field of the first of query results for a given SQL query, or false if empty.
 *
 * @param string $name Name of the field
 * @param string $sql SQL query
 * @return mixed Value of field read.
 */
	public function field($name, $sql) {
		$data = $this->fetchRow($sql);
		if (empty($data[$name])) {
			return false;
		}
		return $data[$name];
	}

/**
 * Empties the method caches.
 * These caches are used by DboSource::name() and DboSource::conditions()
 *
 * @return void
 */
	public function flushMethodCache() {
		$this->_methodCacheChange = true;
		self::$methodCache = array();
	}

/**
 * Cache a value into the methodCaches.  Will respect the value of DboSource::$cacheMethods.
 * Will retrieve a value from the cache if $value is null.
 *
 * If caching is disabled and a write is attempted, the $value will be returned.
 * A read will either return the value or null.
 *
 * @param string $method Name of the method being cached.
 * @param string $key The key name for the cache operation.
 * @param mixed $value The value to cache into memory.
 * @return mixed Either null on failure, or the value if its set.
 */
	public function cacheMethod($method, $key, $value = null) {
		if ($this->cacheMethods === false) {
			return $value;
		}
		if (empty(self::$methodCache)) {
			self::$methodCache = Cache::read('method_cache', '_cake_core_');
		}
		if ($value === null) {
			return (isset(self::$methodCache[$method][$key])) ? self::$methodCache[$method][$key] : null;
		}
		$this->_methodCacheChange = true;
		return self::$methodCache[$method][$key] = $value;
	}

/**
 * Returns a quoted name of $data for use in an SQL statement.
 * Strips fields out of SQL functions before quoting.
 *
 * Results of this method are stored in a memory cache.  This improves performance, but
 * because the method uses a simple hashing algorithm it can infrequently have collisions.
 * Setting DboSource::$cacheMethods to false will disable the memory cache.
 *
 * @param mixed $data Either a string with a column to quote. An array of columns to quote or an
 *   object from DboSource::expression() or DboSource::identifier()
 * @return string SQL field
 */
	public function name($data) {
		if (is_object($data) && isset($data->type)) {
			return $data->value;
		}
		if ($data === '*') {
			return '*';
		}
		if (is_array($data)) {
			foreach ($data as $i => $dataItem) {
				$data[$i] = $this->name($dataItem);
			}
			return $data;
		}
		$cacheKey = crc32($this->startQuote . $data . $this->endQuote);
		if ($return = $this->cacheMethod(__FUNCTION__, $cacheKey)) {
			return $return;
		}
		$data = trim($data);
		if (preg_match('/^[\w-]+(?:\.[^ \*]*)*$/', $data)) { // string, string.string
			if (strpos($data, '.') === false) { // string
				return $this->cacheMethod(__FUNCTION__, $cacheKey, $this->startQuote . $data . $this->endQuote);
			}
			$items = explode('.', $data);
			return $this->cacheMethod(__FUNCTION__, $cacheKey,
				$this->startQuote . implode($this->endQuote . '.' . $this->startQuote, $items) . $this->endQuote
			);
		}
		if (preg_match('/^[\w-]+\.\*$/', $data)) { // string.*
			return $this->cacheMethod(__FUNCTION__, $cacheKey,
				$this->startQuote . str_replace('.*', $this->endQuote . '.*', $data)
			);
		}
		if (preg_match('/^([\w-]+)\((.*)\)$/', $data, $matches)) { // Functions
			return $this->cacheMethod(__FUNCTION__, $cacheKey,
				 $matches[1] . '(' . $this->name($matches[2]) . ')'
			);
		}
		if (
			preg_match('/^([\w-]+(\.[\w-]+|\(.*\))*)\s+' . preg_quote($this->alias) . '\s*([\w-]+)$/i', $data, $matches
		)) {
			return $this->cacheMethod(
				__FUNCTION__, $cacheKey,
				preg_replace(
					'/\s{2,}/', ' ', $this->name($matches[1]) . ' ' . $this->alias . ' ' . $this->name($matches[3])
				)
			);
		}
		if (preg_match('/^[\w-_\s]*[\w-_]+/', $data)) {
			return $this->cacheMethod(__FUNCTION__, $cacheKey, $this->startQuote . $data . $this->endQuote);
		}
		return $this->cacheMethod(__FUNCTION__, $cacheKey, $data);
	}

/**
 * Checks if the source is connected to the database.
 *
 * @return boolean True if the database is connected, else false
 */
	public function isConnected() {
		return $this->connected;
	}

/**
 * Checks if the result is valid
 *
 * @return boolean True if the result is valid else false
 */
	public function hasResult() {
		return is_a($this->_result, 'PDOStatement');
	}

/**
 * Get the query log as an array.
 *
 * @param boolean $sorted Get the queries sorted by time taken, defaults to false.
 * @param boolean $clear If True the existing log will cleared.
 * @return array Array of queries run as an array
 */
	public function getLog($sorted = false, $clear = true) {
		if ($sorted) {
			$log = sortByKey($this->_queriesLog, 'took', 'desc', SORT_NUMERIC);
		} else {
			$log = $this->_queriesLog;
		}
		if ($clear) {
			$this->_queriesLog = array();
		}
		return array('log' => $log, 'count' => $this->_queriesCnt, 'time' => $this->_queriesTime);
	}

/**
 * Outputs the contents of the queries log. If in a non-CLI environment the sql_log element
 * will be rendered and output.  If in a CLI environment, a plain text log is generated.
 *
 * @param boolean $sorted Get the queries sorted by time taken, defaults to false.
 * @return void
 */
	public function showLog($sorted = false) {
		$log = $this->getLog($sorted, false);
		if (empty($log['log'])) {
			return;
		}
		if (PHP_SAPI != 'cli') {
			$controller = null;
			$View = new View($controller, false);
			$View->set('logs', array($this->configKeyName => $log));
			echo $View->element('sql_dump', array('_forced_from_dbo_' => true));
		} else {
			foreach ($log['log'] as $k => $i) {
				print (($k + 1) . ". {$i['query']}\n");
			}
		}
	}

/**
 * Log given SQL query.
 *
 * @param string $sql SQL statement
 * @param array $params Values binded to the query (prepared statements)
 * @return void
 */
	public function logQuery($sql, $params = array()) {
		$this->_queriesCnt++;
		$this->_queriesTime += $this->took;
		$this->_queriesLog[] = array(
			'query'		=> $sql,
			'params'	=> $params,
			'affected'	=> $this->affected,
			'numRows'	=> $this->numRows,
			'took'		=> $this->took
		);
		if (count($this->_queriesLog) > $this->_queriesLogMax) {
			array_pop($this->_queriesLog);
		}
	}

/**
 * Gets full table name including prefix
 *
 * @param mixed $model Either a Model object or a string table name.
 * @param boolean $quote Whether you want the table name quoted.
 * @param boolean $schema Whether you want the schema name included.
 * @return string Full quoted table name
 */
	public function fullTableName($model, $quote = true, $schema = true) {
		if (is_object($model)) {
			$schemaName = $model->schemaName;
			$table = $model->tablePrefix . $model->table;
		} elseif (!empty($this->config['prefix']) && strpos($model, $this->config['prefix']) !== 0) {
			$table = $this->config['prefix'] . strval($model);
		} else {
			$table = strval($model);
		}
		if ($schema && !isset($schemaName)) {
			$schemaName = $this->getSchemaName();
		}

		if ($quote) {
			if ($schema && !empty($schemaName)) {
				if (false == strstr($table, '.')) {
					return $this->name($schemaName) . '.' . $this->name($table);
				}
			}
			return $this->name($table);
		}
		if ($schema && !empty($schemaName)) {
			if (false == strstr($table, '.')) {
				return $schemaName . '.' . $table;
			}
		}
		return $table;
	}

/**
 * The "C" in CRUD
 *
 * Creates new records in the database.
 *
 * @param Model $model Model object that the record is for.
 * @param array $fields An array of field names to insert. If null, $model->data will be
 *   used to generate field names.
 * @param array $values An array of values with keys matching the fields. If null, $model->data will
 *   be used to generate values.
 * @return boolean Success
 */
	public function create(Model $model, $fields = null, $values = null) {
		$id = null;

		if ($fields == null) {
			unset($fields, $values);
			$fields = array_keys($model->data);
			$values = array_values($model->data);
		}
		$count = count($fields);

		for ($i = 0; $i < $count; $i++) {
			$valueInsert[] = $this->value($values[$i], $model->getColumnType($fields[$i]));
			$fieldInsert[] = $this->name($fields[$i]);
			if ($fields[$i] == $model->primaryKey) {
				$id = $values[$i];
			}
		}
		$query = array(
			'table' => $this->fullTableName($model),
			'fields' => implode(', ', $fieldInsert),
			'values' => implode(', ', $valueInsert)
		);

		if ($this->execute($this->renderStatement('create', $query))) {
			if (empty($id)) {
				$id = $this->lastInsertId($this->fullTableName($model, false, false), $model->primaryKey);
			}
			$model->setInsertID($id);
			$model->id = $id;
			return true;
		}
		$model->onError();
		return false;
	}

/**
 * The "R" in CRUD
 *
 * Reads record(s) from the database.
 *
 * @param Model $model A Model object that the query is for.
 * @param array $queryData An array of queryData information containing keys similar to Model::find()
 * @param integer $recursive Number of levels of association
 * @return mixed boolean false on error/failure.  An array of results on success.
 */
	public function read(Model $model, $queryData = array(), $recursive = null) {
		$queryData = $this->_scrubQueryData($queryData);

		$null = null;
		$array = array('callbacks' => $queryData['callbacks']);
		$linkedModels = array();
		$bypass = false;

		if ($recursive === null && isset($queryData['recursive'])) {
			$recursive = $queryData['recursive'];
		}

		if (!is_null($recursive)) {
			$_recursive = $model->recursive;
			$model->recursive = $recursive;
		}

		if (!empty($queryData['fields'])) {
			$bypass = true;
			$queryData['fields'] = $this->fields($model, null, $queryData['fields']);
		} else {
			$queryData['fields'] = $this->fields($model);
		}

		$_associations = $model->associations();

		if ($model->recursive == -1) {
			$_associations = array();
		} elseif ($model->recursive == 0) {
			unset($_associations[2], $_associations[3]);
		}

		foreach ($_associations as $type) {
			foreach ($model->{$type} as $assoc => $assocData) {
				$linkModel = $model->{$assoc};
				$external = isset($assocData['external']);

				$linkModel->getDataSource();
				if ($model->useDbConfig === $linkModel->useDbConfig) {
					if ($bypass) {
						$assocData['fields'] = false;
					}
					if (true === $this->generateAssociationQuery($model, $linkModel, $type, $assoc, $assocData, $queryData, $external, $null)) {
						$linkedModels[$type . '/' . $assoc] = true;
					}
				}
			}
		}

		$query = trim($this->generateAssociationQuery($model, null, null, null, null, $queryData, false, $null));

		$resultSet = $this->fetchAll($query, $model->cacheQueries);
		if ($resultSet === false) {
			$model->onError();
			return false;
		}

		$filtered = array();

		if ($queryData['callbacks'] === true || $queryData['callbacks'] === 'after') {
			$filtered = $this->_filterResults($resultSet, $model);
		}

		if ($model->recursive > -1) {
			foreach ($_associations as $type) {
				foreach ($model->{$type} as $assoc => $assocData) {
					$linkModel = $model->{$assoc};

					if (!isset($linkedModels[$type . '/' . $assoc])) {
						if ($model->useDbConfig === $linkModel->useDbConfig) {
							$db = $this;
						} else {
							$db = ConnectionManager::getDataSource($linkModel->useDbConfig);
						}
					} elseif ($model->recursive > 1 && ($type === 'belongsTo' || $type === 'hasOne')) {
						$db = $this;
					}

					if (isset($db) && method_exists($db, 'queryAssociation')) {
						$stack = array($assoc);
						$db->queryAssociation($model, $linkModel, $type, $assoc, $assocData, $array, true, $resultSet, $model->recursive - 1, $stack);
						unset($db);

						if ($type === 'hasMany') {
							$filtered[] = $assoc;
						}
					}
				}
			}
			if ($queryData['callbacks'] === true || $queryData['callbacks'] === 'after') {
				$this->_filterResults($resultSet, $model, $filtered);
			}
		}

		if (!is_null($recursive)) {
			$model->recursive = $_recursive;
		}
		return $resultSet;
	}

/**
 * Passes association results thru afterFind filters of corresponding model
 *
 * @param array $results Reference of resultset to be filtered
 * @param Model $model Instance of model to operate against
 * @param array $filtered List of classes already filtered, to be skipped
 * @return array Array of results that have been filtered through $model->afterFind
 */
	protected function _filterResults(&$results, Model $model, $filtered = array()) {
		$current = reset($results);
		if (!is_array($current)) {
			return array();
		}
		$keys = array_diff(array_keys($current), $filtered, array($model->alias));
		$filtering = array();
		foreach ($keys as $className) {
			if (!isset($model->{$className}) || !is_object($model->{$className})) {
				continue;
			}
			$linkedModel = $model->{$className};
			$filtering[] = $className;
			foreach ($results as &$result) {
				$data = $linkedModel->afterFind(array(array($className => $result[$className])), false);
				if (isset($data[0][$className])) {
					$result[$className] = $data[0][$className];
				}
			}
		}
		return $filtering;
	}

/**
 * Queries associations.  Used to fetch results on recursive models.
 *
 * @param Model $model Primary Model object
 * @param Model $linkModel Linked model that
 * @param string $type Association type, one of the model association types ie. hasMany
 * @param string $association
 * @param array $assocData
 * @param array $queryData
 * @param boolean $external Whether or not the association query is on an external datasource.
 * @param array $resultSet Existing results
 * @param integer $recursive Number of levels of association
 * @param array $stack
 * @return mixed
 * @throws CakeException when results cannot be created.
 */
	public function queryAssociation(Model $model, &$linkModel, $type, $association, $assocData, &$queryData, $external, &$resultSet, $recursive, $stack) {
		if ($query = $this->generateAssociationQuery($model, $linkModel, $type, $association, $assocData, $queryData, $external, $resultSet)) {
			if (!is_array($resultSet)) {
				throw new CakeException(__d('cake_dev', 'Error in Model %s', get_class($model)));
			}
			if ($type === 'hasMany' && empty($assocData['limit']) && !empty($assocData['foreignKey'])) {
				$ins = $fetch = array();
				foreach ($resultSet as &$result) {
					if ($in = $this->insertQueryData('{$__cakeID__$}', $result, $association, $assocData, $model, $linkModel, $stack)) {
						$ins[] = $in;
					}
				}

				if (!empty($ins)) {
					$ins = array_unique($ins);
					$fetch = $this->fetchAssociated($model, $query, $ins);
				}

				if (!empty($fetch) && is_array($fetch)) {
					if ($recursive > 0) {
						foreach ($linkModel->associations() as $type1) {
							foreach ($linkModel->{$type1} as $assoc1 => $assocData1) {
								$deepModel = $linkModel->{$assoc1};
								$tmpStack = $stack;
								$tmpStack[] = $assoc1;

								if ($linkModel->useDbConfig === $deepModel->useDbConfig) {
									$db = $this;
								} else {
									$db = ConnectionManager::getDataSource($deepModel->useDbConfig);
								}
								$db->queryAssociation($linkModel, $deepModel, $type1, $assoc1, $assocData1, $queryData, true, $fetch, $recursive - 1, $tmpStack);
							}
						}
					}
				}
				if ($queryData['callbacks'] === true || $queryData['callbacks'] === 'after') {
					$this->_filterResults($fetch, $model);
				}
				return $this->_mergeHasMany($resultSet, $fetch, $association, $model, $linkModel);
			} elseif ($type === 'hasAndBelongsToMany') {
				$ins = $fetch = array();
				foreach ($resultSet as &$result) {
					if ($in = $this->insertQueryData('{$__cakeID__$}', $result, $association, $assocData, $model, $linkModel, $stack)) {
						$ins[] = $in;
					}
				}
				if (!empty($ins)) {
					$ins = array_unique($ins);
					if (count($ins) > 1) {
						$query = str_replace('{$__cakeID__$}', '(' . implode(', ', $ins) . ')', $query);
						$query = str_replace('= (', 'IN (', $query);
					} else {
						$query = str_replace('{$__cakeID__$}', $ins[0], $query);
					}
					$query = str_replace(' WHERE 1 = 1', '', $query);
				}

				$foreignKey = $model->hasAndBelongsToMany[$association]['foreignKey'];
				$joinKeys = array($foreignKey, $model->hasAndBelongsToMany[$association]['associationForeignKey']);
				list($with, $habtmFields) = $model->joinModel($model->hasAndBelongsToMany[$association]['with'], $joinKeys);
				$habtmFieldsCount = count($habtmFields);
				$q = $this->insertQueryData($query, null, $association, $assocData, $model, $linkModel, $stack);

				if ($q !== false) {
					$fetch = $this->fetchAll($q, $model->cacheQueries);
				} else {
					$fetch = null;
				}
			}

			$modelAlias = $model->alias;
			$modelPK = $model->primaryKey;
			foreach ($resultSet as &$row) {
				if ($type !== 'hasAndBelongsToMany') {
					$q = $this->insertQueryData($query, $row, $association, $assocData, $model, $linkModel, $stack);
					if ($q !== false) {
						$fetch = $this->fetchAll($q, $model->cacheQueries);
					} else {
						$fetch = null;
					}
				}
				$selfJoin = $linkModel->name === $model->name;

				if (!empty($fetch) && is_array($fetch)) {
					if ($recursive > 0) {
						foreach ($linkModel->associations() as $type1) {
							foreach ($linkModel->{$type1} as $assoc1 => $assocData1) {
								$deepModel = $linkModel->{$assoc1};

								if ($type1 === 'belongsTo' || ($deepModel->alias === $modelAlias && $type === 'belongsTo') || ($deepModel->alias !== $modelAlias)) {
									$tmpStack = $stack;
									$tmpStack[] = $assoc1;
									if ($linkModel->useDbConfig == $deepModel->useDbConfig) {
										$db = $this;
									} else {
										$db = ConnectionManager::getDataSource($deepModel->useDbConfig);
									}
									$db->queryAssociation($linkModel, $deepModel, $type1, $assoc1, $assocData1, $queryData, true, $fetch, $recursive - 1, $tmpStack);
								}
							}
						}
					}
					if ($type === 'hasAndBelongsToMany') {
						$uniqueIds = $merge = array();

						foreach ($fetch as $j => $data) {
							if (isset($data[$with]) && $data[$with][$foreignKey] === $row[$modelAlias][$modelPK]) {
								if ($habtmFieldsCount <= 2) {
									unset($data[$with]);
								}
								$merge[] = $data;
							}
						}
						if (empty($merge) && !isset($row[$association])) {
							$row[$association] = $merge;
						} else {
							$this->_mergeAssociation($row, $merge, $association, $type);
						}
					} else {
						$this->_mergeAssociation($row, $fetch, $association, $type, $selfJoin);
					}
					if (isset($row[$association])) {
						$row[$association] = $linkModel->afterFind($row[$association], false);
					}
				} else {
					$tempArray[0][$association] = false;
					$this->_mergeAssociation($row, $tempArray, $association, $type, $selfJoin);
				}
			}
		}
	}

/**
 * A more efficient way to fetch associations.	Woohoo!
 *
 * @param Model $model Primary model object
 * @param string $query Association query
 * @param array $ids Array of IDs of associated records
 * @return array Association results
 */
	public function fetchAssociated(Model $model, $query, $ids) {
		$query = str_replace('{$__cakeID__$}', implode(', ', $ids), $query);
		if (count($ids) > 1) {
			$query = str_replace('= (', 'IN (', $query);
		}
		return $this->fetchAll($query, $model->cacheQueries);
	}

/**
 * mergeHasMany - Merge the results of hasMany relations.
 *
 *
 * @param array $resultSet Data to merge into
 * @param array $merge Data to merge
 * @param string $association Name of Model being Merged
 * @param Model $model Model being merged onto
 * @param Model $linkModel Model being merged
 * @return void
 */
	protected function _mergeHasMany(&$resultSet, $merge, $association, $model, $linkModel) {
		$modelAlias = $model->alias;
		$modelPK = $model->primaryKey;
		$modelFK = $model->hasMany[$association]['foreignKey'];
		foreach ($resultSet as &$result) {
			if (!isset($result[$modelAlias])) {
				continue;
			}
			$merged = array();
			foreach ($merge as $data) {
				if ($result[$modelAlias][$modelPK] === $data[$association][$modelFK]) {
					if (count($data) > 1) {
						$data = array_merge($data[$association], $data);
						unset($data[$association]);
						foreach ($data as $key => $name) {
							if (is_numeric($key)) {
								$data[$association][] = $name;
								unset($data[$key]);
							}
						}
						$merged[] = $data;
					} else {
						$merged[] = $data[$association];
					}
				}
			}
			$result = Hash::mergeDiff($result, array($association => $merged));
		}
	}

/**
 * Merge association of merge into data
 *
 * @param array $data
 * @param array $merge
 * @param string $association
 * @param string $type
 * @param boolean $selfJoin
 * @return void
 */
	protected function _mergeAssociation(&$data, &$merge, $association, $type, $selfJoin = false) {
		if (isset($merge[0]) && !isset($merge[0][$association])) {
			$association = Inflector::pluralize($association);
		}

		if ($type === 'belongsTo' || $type === 'hasOne') {
			if (isset($merge[$association])) {
				$data[$association] = $merge[$association][0];
			} else {
				if (count($merge[0][$association]) > 1) {
					foreach ($merge[0] as $assoc => $data2) {
						if ($assoc !== $association) {
							$merge[0][$association][$assoc] = $data2;
						}
					}
				}
				if (!isset($data[$association])) {
					if ($merge[0][$association] != null) {
						$data[$association] = $merge[0][$association];
					} else {
						$data[$association] = array();
					}
				} else {
					if (is_array($merge[0][$association])) {
						foreach ($data[$association] as $k => $v) {
							if (!is_array($v)) {
								$dataAssocTmp[$k] = $v;
							}
						}

						foreach ($merge[0][$association] as $k => $v) {
							if (!is_array($v)) {
								$mergeAssocTmp[$k] = $v;
							}
						}
						$dataKeys = array_keys($data);
						$mergeKeys = array_keys($merge[0]);

						if ($mergeKeys[0] === $dataKeys[0] || $mergeKeys === $dataKeys) {
							$data[$association][$association] = $merge[0][$association];
						} else {
							$diff = Hash::diff($dataAssocTmp, $mergeAssocTmp);
							$data[$association] = array_merge($merge[0][$association], $diff);
						}
					} elseif ($selfJoin && array_key_exists($association, $merge[0])) {
						$data[$association] = array_merge($data[$association], array($association => array()));
					}
				}
			}
		} else {
			if (isset($merge[0][$association]) && $merge[0][$association] === false) {
				if (!isset($data[$association])) {
					$data[$association] = array();
				}
			} else {
				foreach ($merge as $i => $row) {
					$insert = array();
					if (count($row) === 1) {
						$insert = $row[$association];
					} elseif (isset($row[$association])) {
						$insert = array_merge($row[$association], $row);
						unset($insert[$association]);
					}

					if (empty($data[$association]) || (isset($data[$association]) && !in_array($insert, $data[$association], true))) {
						$data[$association][] = $insert;
					}
				}
			}
		}
	}

/**
 * Generates an array representing a query or part of a query from a single model or two associated models
 *
 * @param Model $model
 * @param Model $linkModel
 * @param string $type
 * @param string $association
 * @param array $assocData
 * @param array $queryData
 * @param boolean $external
 * @param array $resultSet
 * @return mixed
 */
	public function generateAssociationQuery(Model $model, $linkModel, $type, $association, $assocData, &$queryData, $external, &$resultSet) {
		$queryData = $this->_scrubQueryData($queryData);
		$assocData = $this->_scrubQueryData($assocData);
		$modelAlias = $model->alias;

		if (empty($queryData['fields'])) {
			$queryData['fields'] = $this->fields($model, $modelAlias);
		} elseif (!empty($model->hasMany) && $model->recursive > -1) {
			$assocFields = $this->fields($model, $modelAlias, array("{$modelAlias}.{$model->primaryKey}"));
			$passedFields = $queryData['fields'];
			if (count($passedFields) === 1) {
				if (strpos($passedFields[0], $assocFields[0]) === false && !preg_match('/^[a-z]+\(/i', $passedFields[0])) {
					$queryData['fields'] = array_merge($passedFields, $assocFields);
				} else {
					$queryData['fields'] = $passedFields;
				}
			} else {
				$queryData['fields'] = array_merge($passedFields, $assocFields);
			}
			unset($assocFields, $passedFields);
		}

		if ($linkModel === null) {
			return $this->buildStatement(
				array(
					'fields' => array_unique($queryData['fields']),
					'table' => $this->fullTableName($model),
					'alias' => $modelAlias,
					'limit' => $queryData['limit'],
					'offset' => $queryData['offset'],
					'joins' => $queryData['joins'],
					'conditions' => $queryData['conditions'],
					'order' => $queryData['order'],
					'group' => $queryData['group']
				),
				$model
			);
		}
		if ($external && !empty($assocData['finderQuery'])) {
			return $assocData['finderQuery'];
		}

		$self = $model->name === $linkModel->name;
		$fields = array();

		if ($external || (in_array($type, array('hasOne', 'belongsTo')) && $assocData['fields'] !== false)) {
			$fields = $this->fields($linkModel, $association, $assocData['fields']);
		}
		if (empty($assocData['offset']) && !empty($assocData['page'])) {
			$assocData['offset'] = ($assocData['page'] - 1) * $assocData['limit'];
		}
		$assocData['limit'] = $this->limit($assocData['limit'], $assocData['offset']);

		switch ($type) {
			case 'hasOne':
			case 'belongsTo':
				$conditions = $this->_mergeConditions(
					$assocData['conditions'],
					$this->getConstraint($type, $model, $linkModel, $association, array_merge($assocData, compact('external', 'self')))
				);

				if (!$self && $external) {
					foreach ($conditions as $key => $condition) {
						if (is_numeric($key) && strpos($condition, $modelAlias . '.') !== false) {
							unset($conditions[$key]);
						}
					}
				}

				if ($external) {
					$query = array_merge($assocData, array(
						'conditions' => $conditions,
						'table' => $this->fullTableName($linkModel),
						'fields' => $fields,
						'alias' => $association,
						'group' => null
					));
					$query += array('order' => $assocData['order'], 'limit' => $assocData['limit']);
				} else {
					$join = array(
						'table' => $linkModel,
						'alias' => $association,
						'type' => isset($assocData['type']) ? $assocData['type'] : 'LEFT',
						'conditions' => trim($this->conditions($conditions, true, false, $model))
					);
					$queryData['fields'] = array_merge($queryData['fields'], $fields);

					if (!empty($assocData['order'])) {
						$queryData['order'][] = $assocData['order'];
					}
					if (!in_array($join, $queryData['joins'])) {
						$queryData['joins'][] = $join;
					}
					return true;
				}
			break;
			case 'hasMany':
				$assocData['fields'] = $this->fields($linkModel, $association, $assocData['fields']);
				if (!empty($assocData['foreignKey'])) {
					$assocData['fields'] = array_merge($assocData['fields'], $this->fields($linkModel, $association, array("{$association}.{$assocData['foreignKey']}")));
				}
				$query = array(
					'conditions' => $this->_mergeConditions($this->getConstraint('hasMany', $model, $linkModel, $association, $assocData), $assocData['conditions']),
					'fields' => array_unique($assocData['fields']),
					'table' => $this->fullTableName($linkModel),
					'alias' => $association,
					'order' => $assocData['order'],
					'limit' => $assocData['limit'],
					'group' => null
				);
			break;
			case 'hasAndBelongsToMany':
				$joinFields = array();
				$joinAssoc = null;

				if (isset($assocData['with']) && !empty($assocData['with'])) {
					$joinKeys = array($assocData['foreignKey'], $assocData['associationForeignKey']);
					list($with, $joinFields) = $model->joinModel($assocData['with'], $joinKeys);

					$joinTbl = $model->{$with};
					$joinAlias = $joinTbl;

					if (is_array($joinFields) && !empty($joinFields)) {
						$joinAssoc = $joinAlias = $model->{$with}->alias;
						$joinFields = $this->fields($model->{$with}, $joinAlias, $joinFields);
					} else {
						$joinFields = array();
					}
				} else {
					$joinTbl = $assocData['joinTable'];
					$joinAlias = $this->fullTableName($assocData['joinTable']);
				}
				$query = array(
					'conditions' => $assocData['conditions'],
					'limit' => $assocData['limit'],
					'table' => $this->fullTableName($linkModel),
					'alias' => $association,
					'fields' => array_merge($this->fields($linkModel, $association, $assocData['fields']), $joinFields),
					'order' => $assocData['order'],
					'group' => null,
					'joins' => array(array(
						'table' => $joinTbl,
						'alias' => $joinAssoc,
						'conditions' => $this->getConstraint('hasAndBelongsToMany', $model, $linkModel, $joinAlias, $assocData, $association)
					))
				);
			break;
		}
		if (isset($query)) {
			return $this->buildStatement($query, $model);
		}
		return null;
	}

/**
 * Returns a conditions array for the constraint between two models
 *
 * @param string $type Association type
 * @param Model $model Model object
 * @param string $linkModel
 * @param string $alias
 * @param array $assoc
 * @param string $alias2
 * @return array Conditions array defining the constraint between $model and $association
 */
	public function getConstraint($type, $model, $linkModel, $alias, $assoc, $alias2 = null) {
		$assoc += array('external' => false, 'self' => false);

		if (empty($assoc['foreignKey'])) {
			return array();
		}

		switch (true) {
			case ($assoc['external'] && $type === 'hasOne'):
				return array("{$alias}.{$assoc['foreignKey']}" => '{$__cakeID__$}');
			case ($assoc['external'] && $type === 'belongsTo'):
				return array("{$alias}.{$linkModel->primaryKey}" => '{$__cakeForeignKey__$}');
			case (!$assoc['external'] && $type === 'hasOne'):
				return array("{$alias}.{$assoc['foreignKey']}" => $this->identifier("{$model->alias}.{$model->primaryKey}"));
			case (!$assoc['external'] && $type === 'belongsTo'):
				return array("{$model->alias}.{$assoc['foreignKey']}" => $this->identifier("{$alias}.{$linkModel->primaryKey}"));
			case ($type === 'hasMany'):
				return array("{$alias}.{$assoc['foreignKey']}" => array('{$__cakeID__$}'));
			case ($type === 'hasAndBelongsToMany'):
				return array(
					array("{$alias}.{$assoc['foreignKey']}" => '{$__cakeID__$}'),
					array("{$alias}.{$assoc['associationForeignKey']}" => $this->identifier("{$alias2}.{$linkModel->primaryKey}"))
				);
		}
		return array();
	}

/**
 * Builds and generates a JOIN statement from an array.	 Handles final clean-up before conversion.
 *
 * @param array $join An array defining a JOIN statement in a query
 * @return string An SQL JOIN statement to be used in a query
 * @see DboSource::renderJoinStatement()
 * @see DboSource::buildStatement()
 */
	public function buildJoinStatement($join) {
		$data = array_merge(array(
			'type' => null,
			'alias' => null,
			'table' => 'join_table',
			'conditions' => array()
		), $join);

		if (!empty($data['alias'])) {
			$data['alias'] = $this->alias . $this->name($data['alias']);
		}
		if (!empty($data['conditions'])) {
			$data['conditions'] = trim($this->conditions($data['conditions'], true, false));
		}
		if (!empty($data['table'])) {
			$schema = !(is_string($data['table']) && strpos($data['table'], '(') === 0);
			$data['table'] = $this->fullTableName($data['table'], true, $schema);
		}
		return $this->renderJoinStatement($data);
	}

/**
 * Builds and generates an SQL statement from an array.	 Handles final clean-up before conversion.
 *
 * @param array $query An array defining an SQL query
 * @param Model $model The model object which initiated the query
 * @return string An executable SQL statement
 * @see DboSource::renderStatement()
 */
	public function buildStatement($query, $model) {
		$query = array_merge($this->_queryDefaults, $query);
		if (!empty($query['joins'])) {
			$count = count($query['joins']);
			for ($i = 0; $i < $count; $i++) {
				if (is_array($query['joins'][$i])) {
					$query['joins'][$i] = $this->buildJoinStatement($query['joins'][$i]);
				}
			}
		}
		return $this->renderStatement('select', array(
			'conditions' => $this->conditions($query['conditions'], true, true, $model),
			'fields' => implode(', ', $query['fields']),
			'table' => $query['table'],
			'alias' => $this->alias . $this->name($query['alias']),
			'order' => $this->order($query['order'], 'ASC', $model),
			'limit' => $this->limit($query['limit'], $query['offset']),
			'joins' => implode(' ', $query['joins']),
			'group' => $this->group($query['group'], $model)
		));
	}

/**
 * Renders a final SQL JOIN statement
 *
 * @param array $data
 * @return string
 */
	public function renderJoinStatement($data) {
		extract($data);
		return trim("{$type} JOIN {$table} {$alias} ON ({$conditions})");
	}

/**
 * Renders a final SQL statement by putting together the component parts in the correct order
 *
 * @param string $type type of query being run.  e.g select, create, update, delete, schema, alter.
 * @param array $data Array of data to insert into the query.
 * @return string Rendered SQL expression to be run.
 */
	public function renderStatement($type, $data) {
		extract($data);
		$aliases = null;

		switch (strtolower($type)) {
			case 'select':
				return "SELECT {$fields} FROM {$table} {$alias} {$joins} {$conditions} {$group} {$order} {$limit}";
			case 'create':
				return "INSERT INTO {$table} ({$fields}) VALUES ({$values})";
			case 'update':
				if (!empty($alias)) {
					$aliases = "{$this->alias}{$alias} {$joins} ";
				}
				return "UPDATE {$table} {$aliases}SET {$fields} {$conditions}";
			case 'delete':
				if (!empty($alias)) {
					$aliases = "{$this->alias}{$alias} {$joins} ";
				}
				return "DELETE {$alias} FROM {$table} {$aliases}{$conditions}";
			case 'schema':
				foreach (array('columns', 'indexes', 'tableParameters') as $var) {
					if (is_array(${$var})) {
						${$var} = "\t" . join(",\n\t", array_filter(${$var}));
					} else {
						${$var} = '';
					}
				}
				if (trim($indexes) !== '') {
					$columns .= ',';
				}
				return "CREATE TABLE {$table} (\n{$columns}{$indexes}) {$tableParameters};";
			case 'alter':
				return;
		}
	}

/**
 * Merges a mixed set of string/array conditions
 *
 * @param mixed $query
 * @param mixed $assoc
 * @return array
 */
	protected function _mergeConditions($query, $assoc) {
		if (empty($assoc)) {
			return $query;
		}

		if (is_array($query)) {
			return array_merge((array)$assoc, $query);
		}

		if (!empty($query)) {
			$query = array($query);
			if (is_array($assoc)) {
				$query = array_merge($query, $assoc);
			} else {
				$query[] = $assoc;
			}
			return $query;
		}

		return $assoc;
	}

/**
 * Generates and executes an SQL UPDATE statement for given model, fields, and values.
 * For databases that do not support aliases in UPDATE queries.
 *
 * @param Model $model
 * @param array $fields
 * @param array $values
 * @param mixed $conditions
 * @return boolean Success
 */
	public function update(Model $model, $fields = array(), $values = null, $conditions = null) {
		if ($values == null) {
			$combined = $fields;
		} else {
			$combined = array_combine($fields, $values);
		}

		$fields = implode(', ', $this->_prepareUpdateFields($model, $combined, empty($conditions)));

		$alias = $joins = null;
		$table = $this->fullTableName($model);
		$conditions = $this->_matchRecords($model, $conditions);

		if ($conditions === false) {
			return false;
		}
		$query = compact('table', 'alias', 'joins', 'fields', 'conditions');

		if (!$this->execute($this->renderStatement('update', $query))) {
			$model->onError();
			return false;
		}
		return true;
	}

/**
 * Quotes and prepares fields and values for an SQL UPDATE statement
 *
 * @param Model $model
 * @param array $fields
 * @param boolean $quoteValues If values should be quoted, or treated as SQL snippets
 * @param boolean $alias Include the model alias in the field name
 * @return array Fields and values, quoted and prepared
 */
	protected function _prepareUpdateFields(Model $model, $fields, $quoteValues = true, $alias = false) {
		$quotedAlias = $this->startQuote . $model->alias . $this->endQuote;

		$updates = array();
		foreach ($fields as $field => $value) {
			if ($alias && strpos($field, '.') === false) {
				$quoted = $model->escapeField($field);
			} elseif (!$alias && strpos($field, '.') !== false) {
				$quoted = $this->name(str_replace($quotedAlias . '.', '', str_replace(
					$model->alias . '.', '', $field
				)));
			} else {
				$quoted = $this->name($field);
			}

			if ($value === null) {
				$updates[] = $quoted . ' = NULL';
				continue;
			}
			$update = $quoted . ' = ';

			if ($quoteValues) {
				$update .= $this->value($value, $model->getColumnType($field));
			} elseif ($model->getColumnType($field) == 'boolean' && (is_int($value) || is_bool($value))) {
				$update .= $this->boolean($value, true);
			} elseif (!$alias) {
				$update .= str_replace($quotedAlias . '.', '', str_replace(
					$model->alias . '.', '', $value
				));
			} else {
				$update .= $value;
			}
			$updates[] = $update;
		}
		return $updates;
	}

/**
 * Generates and executes an SQL DELETE statement.
 * For databases that do not support aliases in UPDATE queries.
 *
 * @param Model $model
 * @param mixed $conditions
 * @return boolean Success
 */
	public function delete(Model $model, $conditions = null) {
		$alias = $joins = null;
		$table = $this->fullTableName($model);
		$conditions = $this->_matchRecords($model, $conditions);

		if ($conditions === false) {
			return false;
		}

		if ($this->execute($this->renderStatement('delete', compact('alias', 'table', 'joins', 'conditions'))) === false) {
			$model->onError();
			return false;
		}
		return true;
	}

/**
 * Gets a list of record IDs for the given conditions.	Used for multi-record updates and deletes
 * in databases that do not support aliases in UPDATE/DELETE queries.
 *
 * @param Model $model
 * @param mixed $conditions
 * @return array List of record IDs
 */
	protected function _matchRecords(Model $model, $conditions = null) {
		if ($conditions === true) {
			$conditions = $this->conditions(true);
		} elseif ($conditions === null) {
			$conditions = $this->conditions($this->defaultConditions($model, $conditions, false), true, true, $model);
		} else {
			$noJoin = true;
			foreach ($conditions as $field => $value) {
				$originalField = $field;
				if (strpos($field, '.') !== false) {
					list($alias, $field) = explode('.', $field);
					$field = ltrim($field, $this->startQuote);
					$field = rtrim($field, $this->endQuote);
				}
				if (!$model->hasField($field)) {
					$noJoin = false;
					break;
				}
				if ($field !== $originalField) {
					$conditions[$field] = $value;
					unset($conditions[$originalField]);
				}
			}
			if ($noJoin === true) {
				return $this->conditions($conditions);
			}
			$idList = $model->find('all', array(
				'fields' => "{$model->alias}.{$model->primaryKey}",
				'conditions' => $conditions
			));

			if (empty($idList)) {
				return false;
			}
			$conditions = $this->conditions(array(
				$model->primaryKey => Hash::extract($idList, "{n}.{$model->alias}.{$model->primaryKey}")
			));
		}
		return $conditions;
	}

/**
 * Returns an array of SQL JOIN fragments from a model's associations
 *
 * @param Model $model
 * @return array
 */
	protected function _getJoins(Model $model) {
		$join = array();
		$joins = array_merge($model->getAssociated('hasOne'), $model->getAssociated('belongsTo'));

		foreach ($joins as $assoc) {
			if (isset($model->{$assoc}) && $model->useDbConfig == $model->{$assoc}->useDbConfig && $model->{$assoc}->getDataSource()) {
				$assocData = $model->getAssociated($assoc);
				$join[] = $this->buildJoinStatement(array(
					'table' => $model->{$assoc},
					'alias' => $assoc,
					'type' => isset($assocData['type']) ? $assocData['type'] : 'LEFT',
					'conditions' => trim($this->conditions(
						$this->_mergeConditions($assocData['conditions'], $this->getConstraint($assocData['association'], $model, $model->{$assoc}, $assoc, $assocData)),
						true, false, $model
					))
				));
			}
		}
		return $join;
	}

/**
 * Returns an SQL calculation, i.e. COUNT() or MAX()
 *
 * @param Model $model
 * @param string $func Lowercase name of SQL function, i.e. 'count' or 'max'
 * @param array $params Function parameters (any values must be quoted manually)
 * @return string An SQL calculation function
 */
	public function calculate(Model $model, $func, $params = array()) {
		$params = (array)$params;

		switch (strtolower($func)) {
			case 'count':
				if (!isset($params[0])) {
					$params[0] = '*';
				}
				if (!isset($params[1])) {
					$params[1] = 'count';
				}
				if (is_object($model) && $model->isVirtualField($params[0])) {
					$arg = $this->_quoteFields($model->getVirtualField($params[0]));
				} else {
					$arg = $this->name($params[0]);
				}
				return 'COUNT(' . $arg . ') AS ' . $this->name($params[1]);
			case 'max':
			case 'min':
				if (!isset($params[1])) {
					$params[1] = $params[0];
				}
				if (is_object($model) && $model->isVirtualField($params[0])) {
					$arg = $this->_quoteFields($model->getVirtualField($params[0]));
				} else {
					$arg = $this->name($params[0]);
				}
				return strtoupper($func) . '(' . $arg . ') AS ' . $this->name($params[1]);
			break;
		}
	}

/**
 * Deletes all the records in a table and resets the count of the auto-incrementing
 * primary key, where applicable.
 *
 * @param mixed $table A string or model class representing the table to be truncated
 * @return boolean	SQL TRUNCATE TABLE statement, false if not applicable.
 */
	public function truncate($table) {
		return $this->execute('TRUNCATE TABLE ' . $this->fullTableName($table));
	}

/**
 * Check if the server support nested transactions
 *
 * @return boolean
 */
	public function nestedTransactionSupported() {
		return false;
	}

/**
 * Begin a transaction
 *
 * @return boolean True on success, false on fail
 * (i.e. if the database/model does not support transactions,
 * or a transaction has not started).
 */
	public function begin() {
		if ($this->_transactionStarted) {
			if ($this->nestedTransactionSupported()) {
				return $this->_beginNested();
			}
			$this->_transactionNesting++;
			return $this->_transactionStarted;
		}

		$this->_transactionNesting = 0;
		if ($this->fullDebug) {
			$this->logQuery('BEGIN');
		}
		return $this->_transactionStarted = $this->_connection->beginTransaction();
	}

/**
 * Begin a nested transaction
 *
 * @return boolean
 */
	protected function _beginNested() {
		$query = 'SAVEPOINT LEVEL' . ++$this->_transactionNesting;
		if ($this->fullDebug) {
			$this->logQuery($query);
		}
		$this->_connection->exec($query);
		return true;
	}

/**
 * Commit a transaction
 *
 * @return boolean True on success, false on fail
 * (i.e. if the database/model does not support transactions,
 * or a transaction has not started).
 */
	public function commit() {
		if (!$this->_transactionStarted) {
			return false;
		}

		if ($this->_transactionNesting === 0) {
			if ($this->fullDebug) {
				$this->logQuery('COMMIT');
			}
			$this->_transactionStarted = false;
			return $this->_connection->commit();
		}

		if ($this->nestedTransactionSupported()) {
			return $this->_commitNested();
		}

		$this->_transactionNesting--;
		return true;
	}

/**
 * Commit a nested transaction
 *
 * @return boolean
 */
	protected function _commitNested() {
		$query = 'RELEASE SAVEPOINT LEVEL' . $this->_transactionNesting--;
		if ($this->fullDebug) {
			$this->logQuery($query);
		}
		$this->_connection->exec($query);
		return true;
	}

/**
 * Rollback a transaction
 *
 * @return boolean True on success, false on fail
 * (i.e. if the database/model does not support transactions,
 * or a transaction has not started).
 */
	public function rollback() {
		if (!$this->_transactionStarted) {
			return false;
		}

		if ($this->_transactionNesting === 0) {
			if ($this->fullDebug) {
				$this->logQuery('ROLLBACK');
			}
			$this->_transactionStarted = false;
			return $this->_connection->rollBack();
		}

		if ($this->nestedTransactionSupported()) {
			return $this->_rollbackNested();
		}

		$this->_transactionNesting--;
		return true;
	}

/**
 * Rollback a nested transaction
 *
 * @return boolean
 */
	protected function _rollbackNested() {
		$query = 'ROLLBACK TO SAVEPOINT LEVEL' . $this->_transactionNesting--;
		if ($this->fullDebug) {
			$this->logQuery($query);
		}
		$this->_connection->exec($query);
		return true;
	}

/**
 * Returns the ID generated from the previous INSERT operation.
 *
 * @param mixed $source
 * @return mixed
 */
	public function lastInsertId($source = null) {
		return $this->_connection->lastInsertId();
	}

/**
 * Creates a default set of conditions from the model if $conditions is null/empty.
 * If conditions are supplied then they will be returned.  If a model doesn't exist and no conditions
 * were provided either null or false will be returned based on what was input.
 *
 * @param Model $model
 * @param mixed $conditions Array of conditions, conditions string, null or false. If an array of conditions,
 *   or string conditions those conditions will be returned.  With other values the model's existence will be checked.
 *   If the model doesn't exist a null or false will be returned depending on the input value.
 * @param boolean $useAlias Use model aliases rather than table names when generating conditions
 * @return mixed Either null, false, $conditions or an array of default conditions to use.
 * @see DboSource::update()
 * @see DboSource::conditions()
 */
	public function defaultConditions(Model $model, $conditions, $useAlias = true) {
		if (!empty($conditions)) {
			return $conditions;
		}
		$exists = $model->exists();
		if (!$exists && $conditions !== null) {
			return false;
		} elseif (!$exists) {
			return null;
		}
		$alias = $model->alias;

		if (!$useAlias) {
			$alias = $this->fullTableName($model, false);
		}
		return array("{$alias}.{$model->primaryKey}" => $model->getID());
	}

/**
 * Returns a key formatted like a string Model.fieldname(i.e. Post.title, or Country.name)
 *
 * @param Model $model
 * @param string $key
 * @param string $assoc
 * @return string
 */
	public function resolveKey(Model $model, $key, $assoc = null) {
		if (strpos('.', $key) !== false) {
			return $this->name($model->alias) . '.' . $this->name($key);
		}
		return $key;
	}

/**
 * Private helper method to remove query metadata in given data array.
 *
 * @param array $data
 * @return array
 */
	protected function _scrubQueryData($data) {
		static $base = null;
		if ($base === null) {
			$base = array_fill_keys(array('conditions', 'fields', 'joins', 'order', 'limit', 'offset', 'group'), array());
			$base['callbacks'] = null;
		}
		return (array)$data + $base;
	}

/**
 * Converts model virtual fields into sql expressions to be fetched later
 *
 * @param Model $model
 * @param string $alias Alias table name
 * @param mixed $fields virtual fields to be used on query
 * @return array
 */
	protected function _constructVirtualFields(Model $model, $alias, $fields) {
		$virtual = array();
		foreach ($fields as $field) {
			$virtualField = $this->name($alias . $this->virtualFieldSeparator . $field);
			$expression = $this->_quoteFields($model->getVir