/system/libraries/drivers/Database/Mysql.php

<?php defined('SYSPATH') or die('No direct script access.');
/**
 * MySQL Database Driver
 *
 * $Id: Mysql.php 1931 2008-02-05 22:56:30Z PugFish $
 *
 * @package    Core
 * @author     Kohana Team
 * @copyright  (c) 2007-2008 Kohana Team
 * @license    http://kohanaphp.com/license.html
 */
class Database_Mysql_Driver extends Database_Driver {

	/**
	 * Database connection link
	 */
	protected $link;

	/**
	 * Database configuration
	 */
	protected $db_config;

	/**
	 * Sets the config for the class.
	 *
	 * @param  array  database configuration
	 */
	public function __construct($config)
	{
		$this->db_config = $config;

		Log::add('debug', 'MySQL Database Driver Initialized');
	}

	/**
	 * Closes the database connection.
	 */
	public function __destruct()
	{
		is_resource($this->link) and mysql_close($this->link);
	}

	public function connect()
	{
		// Check if link already exists
		if (is_resource($this->link))
			return $this->link;

		// Import the connect variables
		extract($this->db_config['connection']);

		// Persistent connections enabled?
		$connect = ($this->db_config['persistent'] == TRUE) ? 'mysql_pconnect' : 'mysql_connect';

		// Build the connection info
		$host = isset($host) ? $host : $socket;
		$port = isset($port) ? ':'.$port : '';

		// Make the connection and select the database
		if (($this->link = $connect($host.$port, $user, $pass, TRUE)) AND mysql_select_db($database, $this->link))
		{
			if ($charset = $this->db_config['character_set'])
			{
				$this->set_charset($charset);
			}

			// Clear password after successful connect
			$this->config['connection']['pass'] = NULL;

			return $this->link;
		}

		return FALSE;
	}

	public function query($sql)
	{
		// Only cache if it's turned on, and only cache if it's not a write statement
		if ($this->db_config['cache'] AND ! preg_match('#\b(?:INSERT|UPDATE|REPLACE|SET)\b#i', $sql))
		{
			$hash = $this->query_hash($sql);

			if ( ! isset(self::$query_cache[$hash]))
			{
				// Set the cached object
				self::$query_cache[$hash] = new Mysql_Result(mysql_query($sql, $this->link), $this->link, $this->db_config['object'], $sql);
			}

			// Return the cached query
			return self::$query_cache[$hash];
		}

		return new Mysql_Result(mysql_query($sql, $this->link), $this->link, $this->db_config['object'], $sql);
	}

	public function set_charset($charset)
	{
		$this->query('SET NAMES '.$this->escape_str($charset));
	}

	public function escape_table($table)
	{
		if (stripos($table, ' AS ') !== FALSE)
		{
			// Force 'AS' to uppercase
			$table = str_ireplace(' AS ', ' AS ', $table);

			// Runs escape_table on both sides of an AS statement
			$table = array_map(array($this, __FUNCTION__), explode(' AS ', $table));

			// Re-create the AS statement
			return implode(' AS ', $table);
		}
		return '`'.str_replace('.', '`.`', $table).'`';
	}

	public function escape_column($column)
	{
		if (strtolower($column) == 'count(*)' OR $column == '*')
			return $column;

		// This matches any modifiers we support to SELECT.
		if ( ! preg_match('/\b(?:rand|all|distinct(?:row)?|high_priority|sql_(?:small_result|b(?:ig_result|uffer_result)|no_cache|ca(?:che|lc_found_rows)))\s/i', $column))
		{
			if (stripos($column, ' AS ') !== FALSE)
			{
				// Force 'AS' to uppercase
				$column = str_ireplace(' AS ', ' AS ', $column);

				// Runs escape_column on both sides of an AS statement
				$column = array_map(array($this, __FUNCTION__), explode(' AS ', $column));

				// Re-create the AS statement
				return implode(' AS ', $column);
			}

			return preg_replace('/[^.*]+/', '`$0`', $column);
		}

		$parts = explode(' ', $column);
		$column = '';

		for ($i = 0, $c = count($parts); $i < $c; $i++)
		{
			// The column is always last
			if ($i == ($c - 1))
			{
				$column .= preg_replace('/[^.*]+/', '`$0`', $parts[$i]);
			}
			else // otherwise, it's a modifier
			{
				$column .= $parts[$i].' ';
			}
		}
		return $column;
	}

	public function regex($field, $match = '', $type = 'AND ', $num_regexs)
	{
		$prefix = ($num_regexs == 0) ? '' : $type;

		return $prefix.' '.$this->escape_column($field).' REGEXP \''.$this->escape_str($match).'\'';
	}

	public function notregex($field, $match = '', $type = 'AND ', $num_regexs)
	{
		$prefix = $num_regexs == 0 ? '' : $type;

		return $prefix.' '.$this->escape_column($field).' NOT REGEXP \''.$this->escape_str($match) . '\'';
	}

	public function merge($table, $keys, $values)
	{
		// Escape the column names
		foreach ($keys as $key => $value)
		{
			$keys[$key] = $this->escape_column($value);
		}
		return 'REPLACE INTO '.$this->escape_table($table).' ('.implode(', ', $keys).') VALUES ('.implode(', ', $values).')';
	}

	public function limit($limit, $offset = 0)
	{
		return 'LIMIT '.$offset.', '.$limit;
	}

	public function stmt_prepare($sql = '')
	{
		throw new Kohana_Database_Exception('database.not_implemented', __FUNCTION__);
	}

	public function compile_select($database)
	{
		$sql = ($database['distinct'] == TRUE) ? 'SELECT DISTINCT ' : 'SELECT ';
		$sql .= (count($database['select']) > 0) ? implode(', ', $database['select']) : '*';

		if (count($database['from']) > 0)
		{
			// Escape the tables
			$froms = array();
			foreach ($database['from'] as $from)
				$froms[] = $this->escape_column($from);
			$sql .= "\nFROM ";
			$sql .= implode(', ', $froms);
		}

		if (count($database['join']) > 0)
		{
			$sql .= ' '.implode("\n", $database['join']);
		}

		if (count($database['where']) > 0)
		{
			$sql .= "\nWHERE ";
		}

		$sql .= implode("\n", $database['where']);

		if (count($database['groupby']) > 0)
		{
			$sql .= "\nGROUP BY ";
			$sql .= implode(', ', $database['groupby']);
		}

		if (count($database['having']) > 0)
		{
			$sql .= "\nHAVING ";
			$sql .= implode("\n", $database['having']);
		}

		if (count($database['orderby']) > 0)
		{
			$sql .= "\nORDER BY ";
			$sql .= implode(', ', $database['orderby']);
		}

		if (is_numeric($database['limit']))
		{
			$sql .= "\n";
			$sql .= $this->limit($database['limit'], $database['offset']);
		}

		return $sql;
	}

	public function escape_str($str)
	{
		is_resource($this->link) or $this->connect();

		return mysql_real_escape_string($str, $this->link);
	}

	public function list_tables()
	{
		$sql    = 'SHOW TABLES FROM `'.$this->db_config['connection']['database'].'`';
		$result = $this->query($sql)->result(FALSE, MYSQL_ASSOC);

		$retval = array();
		foreach($result as $row)
		{
			$retval[] = current($row);
		}

		return $retval;
	}

	public function show_error()
	{
		return mysql_error($this->link);
	}

	public function list_fields($table)
	{
		static $tables;

		if (empty($tables[$table]))
		{
			foreach($this->field_data($table) as $row)
			{
				// Make an associative array
				$tables[$table][$row->Field] = $this->sql_type($row->Type);
			}
		}

		return $tables[$table];
	}

	public function field_data($table)
	{
		$query  = mysql_query('SHOW COLUMNS FROM '.$this->escape_table($table), $this->link);

		$table  = array();
		while ($row = mysql_fetch_object($query))
		{
			$table[] = $row;
		}

		return $table;
	}

} // End Database_Mysql_Driver Class


/**
 * MySQL result.
 */
class Mysql_Result implements Database_Result, ArrayAccess, Iterator, Countable {

	/**
	 * Result resource
	 */
	protected $result = NULL;

	/**
	 * Total rows
	 */
	protected $total_rows  = FALSE;

	/**
	 * Current row
	 */
	protected $current_row = FALSE;

	/**
	 * Last insterted ID
	 */
	protected $insert_id = FALSE;

	/**
	 * Fetch type
	 */
	protected $fetch_type  = 'mysql_fetch_object';

	/**
	 * Return type
	 */
	protected $return_type = MYSQL_ASSOC;

	/**
	 * Sets up the result variables.
	 *
	 * @param  resource  query result
	 * @param  resource  database link
	 * @param  boolean   return objects or arrays
	 * @param  string    SQL query that was run
	 */
	public function __construct($result, $link, $object = TRUE, $sql)
	{
		$this->result = $result;

		// If the query is a resource, it was a SELECT, SHOW, DESCRIBE, EXPLAIN query
		if (is_resource($result))
		{
			$this->current_row = 0;
			$this->total_rows  = mysql_num_rows($this->result);
			$this->fetch_type = ($object === TRUE) ? 'mysql_fetch_object' : 'mysql_fetch_array';
		}
		elseif (is_bool($result))
		{
			if ($result == FALSE)
			{
				// SQL error
				throw new Kohana_Database_Exception('database.error', mysql_error($link).' - '.$sql);
			}
			else
			{
				// Its an DELETE, INSERT, REPLACE, or UPDATE query
				$this->insert_id  = mysql_insert_id($link);
				$this->total_rows = mysql_affected_rows($link);
			}
		}

		// Set result type
		$this->result($object);
	}

	/**
	 * Destruct, the cleanup crew!
	 */
	public function __destruct()
	{
		if (is_resource($this->result))
		{
			mysql_free_result($this->result);
		}
	}

	public function result($object = TRUE, $type = MYSQL_ASSOC)
	{
		$this->fetch_type = ((bool) $object) ? 'mysql_fetch_object' : 'mysql_fetch_array';

		// This check has to be outside the previous statement, because we do not
		// know the state of fetch_type when $object = NULL
		// NOTE - The class set by $type must be defined before fetching the result,
		// autoloading is disabled to save a lot of stupid overhead.
		if ($this->fetch_type == 'mysql_fetch_object')
		{
			$this->return_type = class_exists($type, FALSE) ? $type : 'stdClass';
		}
		else
		{
			$this->return_type = $type;
		}

		return $this;
	}

	public function result_array($object = NULL, $type = MYSQL_ASSOC)
	{
		$rows = array();

		if (is_string($object))
		{
			$fetch = $object;
		}
		elseif (is_bool($object))
		{
			if ($object === TRUE)
			{
				$fetch = 'mysql_fetch_object';

				// NOTE - The class set by $type must be defined before fetching the result,
				// autoloading is disabled to save a lot of stupid overhead.
				$type = class_exists($type, FALSE) ? $type : 'stdClass';
			}
			else
			{
				$fetch = 'mysql_fetch_array';
			}
		}
		else
		{
			// Use the default config values
			$fetch = $this->fetch_type;

			if ($fetch == 'mysql_fetch_object')
			{
				$type = class_exists($type, FALSE) ? $type : 'stdClass';
			}
		}

		if (mysql_num_rows($this->result))
		{
			// Reset the pointer location to make sure things work properly
			mysql_data_seek($this->result, 0);

			while ($row = $fetch($this->result, $type))
			{
				$rows[] = $row;
			}
		}

		return isset($rows) ? $rows : array();
	}

	public function insert_id()
	{
		return $this->insert_id;
	}

	public function list_fields()
	{
		$field_names = array();
		while ($field = mysql_fetch_field($this->result))
		{
			$field_names[] = $field->name;
		}

		return $field_names;
	}
	// End Interface


	// Interface: Countable

	/**
	 * Counts the number of rows in the result set.
	 *
	 * @return  integer
	 */
	public function count()
	{
		return $this->total_rows;
	}
	// End Interface


	// Interface: ArrayAccess
	/**
	 * Determines if the requested offset of the result set exists.
	 *
	 * @param   integer  offset id
	 * @return  boolean
	 */
	public function offsetExists($offset)
	{
		if ($this->total_rows > 0)
		{
			$min = 0;
			$max = $this->total_rows - 1;

			return ($offset < $min OR $offset > $max) ? FALSE : TRUE;
		}

		return FALSE;
	}

	/**
	 * Retreives the requested query result offset.
	 *
	 * @param   integer  offset id
	 * @return  mixed
	 */
	public function offsetGet($offset)
	{
		// Check to see if the requested offset exists.
		if ( ! $this->offsetExists($offset))
			return FALSE;

		// Go to the offset
		mysql_data_seek($this->result, $offset);

		// Return the row
		$fetch = $this->fetch_type;
		return $fetch($this->result, $this->return_type);
	}

	/**
	 * Sets the offset with the provided value. Since you can't modify query result sets, this function just throws an exception.
	 *
	 * @param   integer  offset id
	 * @param   integer  value
	 * @throws  Kohana_Database_Exception
	 */
	public function offsetSet($offset, $value)
	{
		throw new Kohana_Database_Exception('database.result_read_only');
	}

	/**
	 * Unsets the offset. Since you can't modify query result sets, this function just throws an exception.
	 *
	 * @param   integer  offset id
	 * @throws  Kohana_Database_Exception
	 */
	public function offsetUnset($offset)
	{
		throw new Kohana_Database_Exception('database.result_read_only');
	}
	// End Interface

	// Interface: Iterator
	/**
	 * Retrieves the current result set row.
	 *
	 * @return  mixed
	 */
	public function current()
	{
		return $this->offsetGet($this->current_row);
	}

	/**
	 * Retreives the current row id.
	 *
	 * @return  integer
	 */
	public function key()
	{
		return $this->current_row;
	}

	/**
	 * Moves the result pointer ahead one step.
	 *
	 * @return  integer
	 */
	public function next()
	{
		return ++$this->current_row;
	}

	/**
	 * Moves the result pointer back one step.
	 *
	 * @return  integer
	 */
	public function prev()
	{
		return --$this->current_row;
	}

	/**
	 * Moves the result pointer to the beginning of the result set.
	 *
	 * @return  integer
	 */
	public function rewind()
	{
		return $this->current_row = 0;
	}

	/**
	 * Determines if the current result pointer is valid.
	 *
	 * @return  boolean
	 */
	public function valid()
	{
		return $this->offsetExists($this->current_row);
	}
	// End Interface
} // End Mysql_Result Class