<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
/**
* CodeIgniter
*
* An open source application development framework for PHP 5.1.6 or newer
*
* @package CodeIgniter
* @author ExpressionEngine Dev Team
* @copyright Copyright (c) 2008 - 2011, EllisLab, Inc.
* @license http://codeigniter.com/user_guide/license.html
* @link http://codeigniter.com
* @since Version 1.0
* @filesource
*/
// ------------------------------------------------------------------------
/**
* Database Result Class
* 数据库结果类
* This is the platform-independent result class.
* This class will not be called directly. Rather, the adapter
* class for the specific database will extend and instantiate it.
* 这是一个平台独立的结果类。
* 这个类不会被直接调用。相反，该适配器
* 类的特定数据库将扩展并创建实例。
* @category Database
* @author ExpressionEngine Dev Team
* @link http://codeigniter.com/user_guide/database/
*/
class CI_DB_result {
var $conn_id = NULL; //数据库链接id
var $result_id = NULL; //返回资源id
var $result_array = array(); //返回数组
var $result_object = array(); //返回的对象
var $custom_result_object = array(); //
var $current_row = 0; //当前的行
var $num_rows = 0; //总记录数
var $row_data = NULL; //
/**
* Query result. Acts as a wrapper function for the following functions.
* 查询结果。作为一个包装函数用于以下功能。
* @access public
* @param string can be "object" or "array" 字符串可以是“对象”或“阵列”
* @return mixed either a result object or array 无论是结果对象或数组
*/
public function result($type = 'object')
{
if ($type == 'array')
return $this->result_array();
else if ($type == 'object')
return $this->result_object();
else
return $this->custom_result_object($type);
}
// --------------------------------------------------------------------
/**
* Custom query result.
* 自定义的查询结果。
* @param class_name A string that represents the type of object you want back
* CLASS_NAME一个字符串，表示对象的类型，你想回来
* @return array of objects
*/
public function custom_result_object($class_name)
{
//在$custom_result_object是否存在$class_name存在这个键值
if (array_key_exists($class_name, $this->custom_result_object))
{
//返回
return $this->custom_result_object[$class_name];
}
//如果返回资源的值为false或者返回数值等于0
if ($this->result_id === FALSE OR $this->num_rows() == 0)
{
return array();
}
// add the data to the object
// 将数据添加到该对象
$this->_data_seek(0); //$this->_data_seek(0)是表示什么呢？这里定义只返回一个true
$result_object = array();
while ($row = $this->_fetch_object())
{
$object = new $class_name(); //实例化这个$class_name();对象
foreach ($row as $key => $value)
{
$object->$key = $value; //将这个对象中的key设置为$value值
}
//然后将这个对象好像就是一条一条记录样，当做一个对象来处理，
//好比以前一条记录是一个数组，但现在的一条记录是一个对象了
$result_object[] = $object;
}
// return the array
// 返回一个数组
return $this->custom_result_object[$class_name] = $result_object;
}
// --------------------------------------------------------------------
/**
* Query result. "object" version.
* 查询结果。 “对象”的版本。
* @access public
* @return object
*/
public function result_object()
{
//如果返回对象大于0时，直接返回
if (count($this->result_object) > 0)
{
return $this->result_object;
}
// In the event that query caching is on the result_id variable
// will return FALSE since there isn't a valid SQL resource so
// we'll simply return an empty array.
// 在事件查询缓存上result_id变量，
// 将返回FALSE，因为没有一个有效的SQL资源
// 我们将简单地返回一个空数组。
if ($this->result_id === FALSE OR $this->num_rows() == 0)
{
return array();
}
$this->_data_seek(0);
//循环该返回对象
while ($row = $this->_fetch_object())
{
$this->result_object[] = $row; //返回result_object()
}
//返回对象数组
return $this->result_object;
}
// --------------------------------------------------------------------
/**
* Query result. "array" version.
* 查询结果。“阵列”的版本。
*
* @access public
* @return array
*/
public function result_array()
{
if (count($this->result_array) > 0)
{
return $this->result_array;
}
// In the event that query caching is on the result_id variable
// will return FALSE since there isn't a valid SQL resource so
// we'll simply return an empty array.
// 在事件查询缓存上result_id变量，
// 将返回FALSE，因为没有一个有效的SQL资源
// 我们将简单地返回一个空数组。
if ($this->result_id === FALSE OR $this->num_rows() == 0)
{
return array();
}
$this->_data_seek(0);
//$this->_fetch_assoc() 返回一个关联数组
while ($row = $this->_fetch_assoc())
{
$this->result_array[] = $row;
}
return $this->result_array;
}
// --------------------------------------------------------------------
/**
* Query result. Acts as a wrapper function for the following functions.
* 查询结果。作为一个包装函数用于以下功能。
*
* @access public
* @param string
* @param string can be "object" or "array" 可以是“对象”或“阵列”
* @return mixed either a result object or array 无论是结果对象或数组
*/
public function row($n = 0, $type = 'object')
{
//如果$n不为数值型
if ( ! is_numeric($n))
{
// We cache the row data for subsequent uses 缓存的行数据的后续使用
if ( ! is_array($this->row_data))
{
$this->row_data = $this->row_array(0);
}
// array_key_exists() instead of isset() to allow for MySQL NULL values
//array_key_exists（）isset（）的，而不是让MySQL的NULL值
if (array_key_exists($n, $this->row_data))
{
return $this->row_data[$n];
}
// reset the $n variable if the result was not achieved
// 如果结果没有达到复位的$ n变量
$n = 0;
}
if ($type == 'object')
return $this->row_object($n);
else if ($type == 'array')
return $this->row_array($n);
else
return $this->custom_row_object($n, $type);
}
// --------------------------------------------------------------------
/**
* Assigns an item into a particular column slot
* 分配一个项目到一个特定的列插槽
* @access public
* @return object
*/
public function set_row($key, $value = NULL)
{
// We cache the row data for subsequent uses
// 缓存的行数据的后续使用
if ( ! is_array($this->row_data))
{
$this->row_data = $this->row_array(0);
}
if (is_array($key))
{
foreach ($key as $k => $v)
{
$this->row_data[$k] = $v;
}
return;
}
if ($key != '' AND ! is_null($value))
{
$this->row_data[$key] = $value;
}
}
// --------------------------------------------------------------------
/**
* Returns a single result row - custom object version
* 返回一个结果行 - 自定义对象的版本
* @access public
* @return object
*/
public function custom_row_object($n, $type)
{
//$this->custom_result_object($type) //自定义查结果
$result = $this->custom_result_object($type);
//如果为空值
if (count($result) == 0)
{
return $result;
}
//
if ($n != $this->current_row AND isset($result[$n]))
{
$this->current_row = $n; //更新当前使用的记录
}
//返回$result中当前使用的记录集
return $result[$this->current_row];
}
/**
* Returns a single result row - object version
* 返回一个结果行 - 对象版本
* @access public
* @return object
*/
public function row_object($n = 0)
{
$result = $this->result_object();
if (count($result) == 0)
{
return $result;
}
if ($n != $this->current_row AND isset($result[$n]))
{
$this->current_row = $n;
}
return $result[$this->current_row];
}
// --------------------------------------------------------------------
/**
* Returns a single result row - array version
* 返回一个结果行 - 数组版本
* @access public
* @return array
*/
public function row_array($n = 0)
{
$result = $this->result_array();
if (count($result) == 0)
{
return $result;
}
if ($n != $this->current_row AND isset($result[$n]))
{
$this->current_row = $n;
}
return $result[$this->current_row];
}
// --------------------------------------------------------------------
/**
* Returns the "first" row
* 返回“第一”行
* @access public
* @return object
*/
public function first_row($type = 'object')
{
$result = $this->result($type);
if (count($result) == 0)
{
return $result;
}
return $result[0];
}
// --------------------------------------------------------------------
/**
* Returns the "last" row
* 返回最后一行
* @access public
* @return object
*/
public function last_row($type = 'object')
{
$result = $this->result($type);
if (count($result) == 0)
{
return $result;
}
return $result[count($result) -1];
}
// --------------------------------------------------------------------
/**
* Returns the "next" row
* 返回下一条数据
* @access public
* @return object
*/
public function next_row($type = 'object')
{
$result = $this->result($type);
if (count($result) == 0)
{
return $result;
}
//如果当前存在当前值的下一个元素
if (isset($result[$this->current_row + 1]))
{
++$this->current_row;
}
return $result[$this->current_row];
}
// --------------------------------------------------------------------
/**
* Returns the "previous" row
* 返回“先前”行
* @access public
* @return object
*/
public function previous_row($type = 'object')
{
$result = $this->result($type);
if (count($result) == 0)
{
return $result;
}
if (isset($result[$this->current_row - 1]))
{
--$this->current_row;
}
return $result[$this->current_row];
}
// --------------------------------------------------------------------
/**
* The following functions are normally overloaded by the identically named
* methods in the platform-specific driver -- except when query caching
* is used. When caching is enabled we do not load the other driver.
* These functions are primarily here to prevent undefined function errors
* when a cached result object is in use. They are not otherwise fully
* operational due to the unavailability of the database resource IDs with
* cached results.
* 以下功能相同的命名通常超载
* 特定于平台的驱动程序的方法 - 除了当查询缓存
* 被使用。当缓存被启用，我们不加载其他驱动程序。
* 这些功能主要是防止函数未定义错误
* 当对象是使用一个缓存的结果。他们不完全
* 经营由于数据库资源ID无法与
* 高速缓存的结果。
*/
public function num_rows() { return $this->num_rows; }
public function num_fields() { return 0; }
public function list_fields() { return array(); }
public function field_data() { return array(); }
public function free_result() { return TRUE; }
protected function _data_seek() { return TRUE; }
protected function _fetch_assoc() { return array(); }
protected function _fetch_object() { return array(); }
}
// END DB_result class
/* End of file DB_result.php */
/* Location: ./system/database/DB_result.php */
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