/system/database/drivater/postgre/postgre_result.php Postgres的结果类

<?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
 */

// ------------------------------------------------------------------------

/**
 * Postgres Result Class
 * Postgres的结果类
 * 
 * This class extends the parent result class: CI_DB_result
 * 这个类继承父结果类：CI_DB_result
 * @category	Database
 * @author		ExpressionEngine Dev Team
 * @link		http://codeigniter.com/user_guide/database/
 */
class CI_DB_postgre_result extends CI_DB_result {

	/**
	 * Number of rows in the result set
	 * 在结果集中的行数 pg_num_rows($this->result_id);
	 * @access	public
	 * @return	integer
	 */
	function num_rows()
	{
		return @pg_num_rows($this->result_id);
	}

	// --------------------------------------------------------------------

	/**
	 * Number of fields in the result set
	 * 取得结果集中的字段值 pg_num_fields($this->result_id)
	 * @access	public
	 * @return	integer
	 */
	function num_fields()
	{
		return @pg_num_fields($this->result_id);
	}

	// --------------------------------------------------------------------

	/**
	 * Fetch Field Names 取字段名..
	 * 循环结果集中字段的名称
	 * Generates an array of column names
	 * 生成数组的列名
	 * @access	public
	 * @return	array
	 */
	function list_fields()
	{
		$field_names = array();
		//$this->num_fields() 取得当前的字段值的总数
		for ($i = 0; $i < $this->num_fields(); $i++)
		{
			//pg_field_name($this->result_id, $i); 第一个参数是查询的结果，第二是字段的索引值
			$field_names[] = pg_field_name($this->result_id, $i);
		}

		return $field_names;
	}

	// --------------------------------------------------------------------

	/**
	 * Field data
	 * 现场数据
	 * Generates an array of objects containing field meta-data
	 * 生成数组包含元数据领域的对象
	 * @access	public
	 * @return	array
	 */
	function field_data()
	{
		$retval = array();
		//取得每组数据的值
		for ($i = 0; $i < $this->num_fields(); $i++)
		{
			$F				= new stdClass();
			//名称
			$F->name		= pg_field_name($this->result_id, $i);
			//类型
			$F->type		= pg_field_type($this->result_id, $i);
			//最大长度
			$F->max_length	= pg_field_size($this->result_id, $i);
			//是否为主键
			$F->primary_key = 0;
			//默认值
			$F->default		= '';

			$retval[] = $F;
		}

		return $retval;
	}

	// --------------------------------------------------------------------

	/**
	 * Free the result
	 * 释放查询结构
	 * @return	null
	 */
	function free_result()
	{
		//如果is_resource($this->result_id)
		if (is_resource($this->result_id))
		{
			pg_free_result($this->result_id); //释放 pg_free_result()
			$this->result_id = FALSE;
		}
	}

	// --------------------------------------------------------------------

	/**
	 * Data Seek
	 * 搜索数据
	 * 
	 * Moves the internal pointer to the desired offset.  We call
	 * this internally before fetching results to make sure the
	 * result set starts at zero
	 * 
	 * 内部指针移动到所需的偏移。我们称之为此之前，内部取结果，以确保结果集从零开始
	 * @access	private
	 * @return	array
	 */
	function _data_seek($n = 0)
	{
		//将指针设置到查询资源的指定位置
		return pg_result_seek($this->result_id, $n);
	}

	// --------------------------------------------------------------------

	/**
	 * Result - associative array
	 * 结果 - 关联数组
	 * Returns the result set as an array
	 * 返回的结果集作为一个数组，  pg_fetch_assoc(); mysql_fetch_assoc();
	 * @access	private
	 * @return	array
	 */
	function _fetch_assoc()
	{
		return pg_fetch_assoc($this->result_id);
	}

	// --------------------------------------------------------------------

	/**
	 * Result - object
	 * 返回一个对象
	 * Returns the result set as an object
	 * pg_fetch_object($this->result_id); 
	 * @access	private
	 * @return	object
	 */
	function _fetch_object()
	{
		return pg_fetch_object($this->result_id);
	}

}


/* End of file postgre_result.php */
/* Location: ./system/database/drivers/postgre/postgre_result.php */