Mysql 数据库访问类

Mysql数据库访问类 实现代码，对于想学习mysql操作类的朋友值得一看

/**
* @Purpose: Mysql数据库访问类
* @Package:
* @Author: lisen@sellingclub.cn
* @Modifications:
* @See:
* @Time: 2008.10.10
*/
class DB_MYSQL
{
//============================================================
private $Host = 'localhost';
private $Database = 'db_name';
private $User = 'user';
private $Password = 'password';
//============================================================
private $Link_Id = 0; //数据库连接
private $Query_Id = 0; //查询结果
private $Row_Result = array(); //结果集组成的数组
private $Field_Result = array(); //结果集字段组成的数组
private $Affected_Rows; //影响的行数
private $Rows; //结果集中记录的行数
private $Fields; //结果集中字段数
private $Row_Postion = 0; //记录指针位置索引
public $Insert_Id = 0;
//************************************************************
/**** 构造函数 ****/
function __construct()
{
$this->connect();
}
/**** 析构函数 ****/
function __destruct()
{
@mysql_free_result($this->Query_Id);
mysql_close($this->Link_Id);
}
/**** 连接服务器,选择数据库 ****/
function connect($Database = '',$Host = '',$User = '',$Password = '')
{
$Database = $Database == '' ? $this->Database : $Database;
$Host = $Host == '' ? $this->Host : $Host;
$User = $User == '' ? $this->User : $User;
$Password = $Password == '' ? $this->Password : $Password;
//-----------------------------------------------------------//
if(0 == $this->Link_Id)
{
$this->Link_Id = @mysql_pconnect($Host,$User,$Password);
if(!$this->Link_Id)
{
$this->halt('连接数据库服务端失败!');
}
if(!mysql_select_db($this->Database,$this->Link_Id))
{
$this->halt('不能打开指定的数据库：'.$this->Database);
}
}
return $this->Link_Id;
}
/**** 释放内存 ****/
function free()
{
if(@mysql_free_result($this->Query_Id))
{
unset($this->Row_Result);
}
$this->Query_Id = 0;
}
/**** 执行查询 ****/
function query($Query_String)
{
//释放上次查询内存
if($this->Query_Id)
{
$this->free();
}
if(0 == $this->Link_Id)
{
$this->connect();
}
//设置中文字符集
@mysql_query('set names gb2312');
$this->Query_Id = mysql_query($Query_String,$this->Link_Id);
$this->Insert_Id = mysql_insert_id();
if(!$this->Query_Id)
{
$this->halt('SQL查询语句出错：'.$Query_String);
}
@mysql_query('set names gb2312');
return $this->Query_Id;
}
/**** 将结果集指针指向指定行 ****/
function seek($pos)
{
if(@mysql_data_seek($this->Query_Id,$pos))
{
$this->Row_Position = $pos;
return true;
}
else
{
$this->halt('定位结果集发生错误!');
return false;
}
}
/**** 返回结果集组成的数组 ****/
function get_rows_array()
{
$this->get_rows();
for($i = 0; $i < $this->Rows; $i++)
{
if(!mysql_data_seek($this->Query_Id,$i))
{
$this->halt('mysql_data_seek 查询出错!');
}
$this->Row_Result[$i] = mysql_fetch_array($this->Query_Id);
}
return $this->Row_Result;
}
/**** 返回结果集字段组成的数组 ****/
function get_fields_array()
{
$this->get_fields();
for($i = 0; $i < $this->Fields; $i++)
{
$obj = mysql_fetch_field($this->Query_Id,$i);
$this->Field_Result[$i] = $obj->name;
}
return $this->Field_Result;
}
/**** 返回影响记录数 ****/
function get_affected_rows()
{
$this->Affected_Rows = mysql_affected_rows($this->Link_Id);
return $this->Affected_Rows;
}
/**** 返回结果集中的记录数 ****/
function get_rows()
{
$this->Rows = mysql_num_rows($this->Query_Id);
return $this->Rows;
}
/**** 返回结果集中的字段个数 ****/
function get_fields()
{
$this->Fields = mysql_num_fields($this->Query_Id);
return $this->Fields;
}
/**** 执行sql语句并返回由查询结果中第一行记录组成的数组 ****/
function fetch_one_array($sql)
{ @mysql_query('set names gb2312');
$this->query($sql);
return mysql_fetch_array($this->Query_Id);
}
/**** 打印错误信息 ****/
function halt($msg)
{
$this->Error = mysql_error();
printf(" 数据库发生错误： %s \n",$msg);
printf("MySQL 返回错误信息： %s \n",$this->Error);
printf("错误页面：%s \n",$_SERVER['PHP_SELF']);
printf(" 请将错误信息提交到系统管理员或网站程序员处理! \n");
die('脚本终止');
}
}