Mysql数据库操作类( 1127版，提供源码下载 )

Mysql数据库操作类，学习php的朋友可以参考下。

 
<?php 
class Mysql { 
private $db_host; //主机地址 
private $db_user; //用户名 
private $db_pass; //连接密码 
private $db_name; //名称 
private $db_charset; //编码 
private $conn; 
public $debug=false;//调试开关，默认关闭 
private $query_id; //用于判断sql语句是否执行成功 
private $result; //结果集 
private $num_rows; //结果集中行的数目，仅对select有效 
private $insert_id; //上一步 INSERT 操作产生的 ID 
// 构造/析构函数 
function __construct ($db_host,$db_user,$db_pass,$db_name,$db_charset,$conn) { 
$this->db_host = $db_host ; 
$this->db_user = $db_user ; 
$this->db_pass = $db_pass ; 
$this->db_name = $db_name ; 
$this->db_charset = $db_charset ; 
$this->conn = $conn ; 
$this->connect(); 
} 
function __destruct () { 
@mysql_close($this->conn); 
} 
// 连接/选择数据库 
public function connect () { 
if ($this->conn == 'pconn') { 
@$this->conn = mysql_pconnect($this->db_host,$this->db_user,$this->db_pass); 
} else { 
@$this->conn = mysql_connect($this->db_host,$this->db_user,$this->db_pass); 
} 
if (!$this->conn) { 
$this->show_error('数据库-连接失败：用户名或密码错误！'); 
} 
if (!@mysql_select_db($this->db_name,$this->conn)) { 
$this->show_error("数据库-选择失败：数据库 $this->db_name 不可用"); 
} 
mysql_query("SET NAMES $this->db_charset"); 
return $this->conn; 
} 
// query方法 
public function query ($sql) { 
if ($this->query_id) $this->free_result(); 
$this->query_id = @mysql_query($sql,$this->conn); 
if (!$this->query_id) $this->show_error("SQL语句 <b>\"$sql\"</b> 执行时遇到错误"); 
return $this->query_id; 
} 
// 显示详细错误信息 
public function show_error ($msg) { 
if($this->debug){ 
$errinfo = mysql_error(); 
echo "错误：$msg <br/> 返回：$errinfo<p>"; 
}else{ 
echo '<p>出现错误！<p>'; 
} 
} 
// 获得query执行成功与否的信息 
public function get_query_info($info){ 
if ($this->query_id) { 
echo $info; 
} 
} 
// 查询所有 
public function findall ($table_name) { 
$this->query("select * from $table_name"); 
} 
// mysql_fetch_array 
public function fetch_array () { 
if ($this->query_id) { 
$this->result = mysql_fetch_array($this->query_id); 
return $this->result; 
} 
} 
// ...... 
public function fetch_assoc () { 
if ($this->query_id) { 
$this->result = mysql_fetch_assoc($this->query_id); 
return $this->result; 
} 
} 
public function fetch_row () { 
if ($this->query_id) { 
$this->result = mysql_fetch_row($this->query_id); 
return $this->result; 
} 
} 
public function fetch_object () { 
if ($this->query_id) { 
$this->result = mysql_fetch_object($this->query_id); 
return $this->result; 
} 
} 
// 获取 num_rows 
public function num_rows () { 
if ($this->query_id) { 
$this->num_rows = mysql_num_rows($this->query_id); 
return $this->num_rows; 
} 
} 
// 获取 insert_id 
public function insert_id () { 
return $this->insert_id = mysql_insert_id(); 
} 
// 显示共有多少张表 
public function show_tables () { 
$this->query("show tables"); 
if ($this->query_id) { 
echo "数据库 $this->db_name 共有 ".$this->num_rows($this->query_id)." 张表<br/>"; 
$i = 1; 
while ($row = $this->fetch_array($this->query_id)){ 
echo "$i -- $row[0]<br/>"; 
$i ++; 
} 
} 
} 
// 显示共有多少个数据库 
public function show_dbs(){ 
$this->query("show databases"); 
if ($this->query_id) { 
echo "共有数据库 ".$this->num_rows($this->query_id)." 个<br/>"; 
$i = 1; 
while ($this->row = $this->fetch_array($this->query_id)){ 
echo "$i -- ".$this->row[Database]."<br />"; 
$i ++; 
} 
} 
} 
// 删除数据库：返回删除结果 
public function drop_db ($db_name='') { 
if ($db_name == '') { 
$db_name = $this->db_name;//默认删除当前数据库 
$this->query("DROP DATABASE $db_name"); 
}else { 
$this->query("DROP DATABASE $db_name"); 
} 
if ($this->query_id) { 
return "数据库 $db_name 删除成功"; 
}else { 
$this->show_error("数据库 $db_name 删除失败"); 
} 
} 
// 删除数据表：返回删除结果 
public function drop_table ($table_name) { 
$this->query("DROP TABLE $table_name"); 
if ($this->query_id) { 
return "数据表 $table_name 删除成功"; 
}else { 
$this->show_error("数据表 $table_name 删除失败"); 
} 
} 
// 创建数据库 
public function create_db ($db_name) { 
$this->query("CREATE DATABASE $db_name"); 
if($this->query_id){ 
return "数据库 $db_name 创建成功"; 
}else { 
$this->show_error("数据库 $db_name 创建失败"); 
} 
} 
// 获取数据库版本 
public function get_info(){ 
echo mysql_get_server_info(); 
} 
// 释放内存 
public function free_result () { 
if ( @mysql_free_result($this->query_id) ) 
unset ($this->result); 
$this->query_id = 0; 
} 
} // End class 
?>