经典的mysql数据库连接操作类

php
class mysql {
 private $db_host; //数据库主机
 private $db_user; //数据库用户名
 private $db_pwd; //数据库用户名密码
 private $db_database; //数据库名
 private $conn; //数据库连接标识;
 private $result; //执行query命令的结果资源标识
 private $sql; //sql执行语句
 private $row; //返回的条目数
 private $coding; //数据库编码，GBK,UTF8,gb2312
 private $bulletin = true; //是否开启错误记录
 private $show_error = true; //测试阶段，显示所有错误,具有安全隐患,默认关闭
 private $is_error = false; //发现错误是否立即终止,默认true,建议不启用，因为当有问题时用户什么也看不到是很苦恼的

 /*构造函数*/
 public function __construct($db_host, $db_user, $db_pwd, $db_database, $conn, $coding) {
  $this->db_host = $db_host;
  $this->db_user = $db_user;
  $this->db_pwd = $db_pwd;
  $this->db_database = $db_database;
  $this->conn = $conn;
  $this->coding = $coding;
  $this->connect();
 }

 /*数据库连接*/
 public function connect() {
  if ($this->conn == "pconn") {
   //永久链接
   $this->conn = mysql_pconnect($this->db_host, $this->db_user, $this->db_pwd);
  } else {
   //即使链接
   $this->conn = mysql_connect($this->db_host, $this->db_user, $this->db_pwd);
  }

  if (!mysql_select_db($this->db_database, $this->conn)) {
   if ($this->show_error) {
    $this->show_error("数据库不可用：", $this->db_database);
   }
  }
  mysql_query("SET NAMES $this->coding");
 }

 /*数据库执行语句，可执行查询添加修改删除等任何sql语句*/
 public function query($sql) {
  if ($sql == "") {
   $this->show_error("SQL语句错误：", "SQL查询语句为空");
  }
  $this->sql = $sql;

  $result = mysql_query($this->sql, $this->conn);

  if (!$result) {
   //调试中使用，sql语句出错时会自动打印出来
   if ($this->show_error) {
    $this->show_error("错误SQL语句：", $this->sql);
   }
  } else {
   $this->result = $result;
  }
  return $this->result;
 }

 /*创建添加新的数据库*/
 public function create_database($database_name) {
  $database = $database_name;
  $sqlDatabase = 'create database ' . $database;
  $this->query($sqlDatabase);
 }

 /*查询服务器所有数据库*/
 //将系统数据库与用户数据库分开，更直观的显示？
 public function show_databases() {
  $this->query("show databases");
  echo "现有数据库：" . $amount = $this->db_num_rows($rs);
  echo "
";
  $i = 1;
  while ($row = $this->fetch_array($rs)) {
   echo "$i $row[Database]";
   echo "
";
   $i++;
  }
 }

 //以数组形式返回主机中所有数据库名
 public function databases() {
  $rsPtr = mysql_list_dbs($this->conn);
  $i = 0;
  $cnt = mysql_num_rows($rsPtr);
  while ($i < $cnt) {
   $rs[] = mysql_db_name($rsPtr, $i);
   $i++;
  }
  return $rs;
 }

 /*查询数据库下所有的表*/
 public function show_tables($database_name) {
  $this->query("show tables");
  echo "现有数据库：" . $amount = $this->db_num_rows($rs);
  echo "
";
  $i = 1;
  while ($row = $this->fetch_array($rs)) {
   $columnName = "Tables_in_" . $database_name;
   echo "$i $row[$columnName]";
   echo "
";
   $i++;
  }
 }

 /*
 mysql_fetch_row()    array  $row[0],$row[1],$row[2]
 mysql_fetch_array()  array  $row[0] 或 $row[id]
 mysql_fetch_assoc()  array  用$row->content 字段大小写敏感
 mysql_fetch_object() object 用$row[id],$row[content] 字段大小写敏感
 */

 /*取得结果数据*/
 public function mysql_result_li() {
  return mysql_result($str);
 }

 /*取得记录集,获取数组-索引和关联,使用$row['content'] */

 public function fetch_array() {
  return mysql_fetch_array($this->result);
 }

// public function fetch_array($query) {
//  return mysql_fetch_array($query);
// }

 //获取关联数组,使用$row['字段名']
 public function fetch_assoc() {
  return mysql_fetch_assoc($this->result);
 }

 //获取数字索引数组,使用$row[0],$row[1],$row[2]
 public function fetch_row() {
  return mysql_fetch_row($this->result);
 }

 //获取对象数组,使用$row->content
 public function fetch_Object() {
  return mysql_fetch_object($this->result);
 }

 //简化查询select
 public function findall($table) {
  $this->query("SELECT * FROM $table");
 }

 //简化查询select
 public function select($table, $columnName = "*", $condition = '', $debug = '') {
  $condition = $condition ? ' Where ' . $condition : NULL;
  if ($debug) {
   echo "SELECT $columnName FROM $table $condition";
  } else {
   $this->query("SELECT $columnName FROM $table $condition");
  }
 }

 //简化删除del
 public function delete($table, $condition, $url = '') {
  if ($this->query("DELETE FROM $table WHERE $condition")) {
   if (!empty ($url))
    $this->Get_admin_msg($url, '删除成功！');
  }
 }

 //简化插入insert
 public function insert($table, $columnName, $value, $url = '') {
  if ($this->query("INSERT INTO $table ($columnName) VALUES ($value)")) {
   if (!empty ($url))
    $this->Get_admin_msg($url, '添加成功！');
  }
 }

 //简化修改update
 public function update($table, $mod_content, $condition, $url = '') {
  //echo "UPDATE $table SET $mod_content WHERE $condition"; exit();
  if ($this->query("UPDATE $table SET $mod_content WHERE $condition")) {
   if (!empty ($url))
    $this->Get_admin_msg($url);
  }
 }

 /*取得上一步 INSERT 操作产生的 ID*/
 public function insert_id() {
  return mysql_insert_id();
 }

 //指向确定的一条数据记录
 public function db_data_seek($id) {
  if ($id > 0) {
   $id = $id -1;
  }
  if (!@ mysql_data_seek($this->result, $id)) {
   $this->show_error("SQL语句有误：", "指定的数据为空");
  }
  return $this->result;
 }

 // 根据select查询结果计算结果集条数
/* public function db_num_rows() {
  if ($this->result == null) {
   if ($this->show_error) {
    $this->show_error("SQL语句错误", "暂时为空，没有任何内容！");
   }
  } else {
   return mysql_num_rows($this->result);
  }
 }*/
 public function db_num_rows($result){
  if($result==null){
  if ($this->show_error) {
    $this->show_error("SQL语句错误", "暂时为空，没有任何内容！");
   }
  }else{
   return mysql_num_rows($result);
  }
 }

 // 根据insert,update,delete执行结果取得影响行数
 public function db_affected_rows() {
  return mysql_affected_rows();
 }

 //输出显示sql语句
 public function show_error($message = "", $sql = "") {
  if (!$sql) {
   echo "" . $message . "";
   echo "
";
  } else {
   echo "

" . $sql . "

  echo "
";
 }

 //释放结果集
 public function free() {
  @ mysql_free_result($this->result);
 }

 //数据库选择
 public function select_db($db_database) {
  return mysql_select_db($db_database);
 }

 //查询字段数量
 public function num_fields($table_name) {
  //return mysql_num_fields($this->result);
  $this->query("select * from $table_name");
  echo "
";
  echo "字段数：" . $total = mysql_num_fields($this->result);
  echo "

";

  for ($i = 0; $i < $total; $i++) {

   print_r(mysql_fetch_field($this->result, $i));

  }

  echo "

 //取得 MySQL 服务器信息
 public function mysql_server($num = '') {
  switch ($num) {
   case 1 :
    return mysql_get_server_info(); //MySQL 服务器信息
    break;

   case 2 :
    return mysql_get_host_info(); //取得 MySQL 主机信息
    break;

   case 3 :
    return mysql_get_client_info(); //取得 MySQL 客户端信息
    break;

   case 4 :
    return mysql_get_proto_info(); //取得 MySQL 协议信息
    break;

   default :
    return mysql_get_client_info(); //默认取得mysql版本信息
  }
 }

 //析构函数，自动关闭数据库,垃圾回收机制
 public function __destruct() {
  if (!empty ($this->result)) {
   $this->free();
  }
  mysql_close($this->conn);
 } //function __destruct();

 /*获得客户端真实的IP地址*/
 function getip() {
  if (getenv("HTTP_CLIENT_IP") && strcasecmp(getenv("HTTP_CLIENT_IP"), "unknown")) {
   $ip = getenv("HTTP_CLIENT_IP");
  } else
   if (getenv("HTTP_X_FORWARDED_FOR") && strcasecmp(getenv("HTTP_X_FORWARDED_FOR"), "unknown")) {
    $ip = getenv("HTTP_X_FORWARDED_FOR");
   } else
    if (getenv("REMOTE_ADDR") && strcasecmp(getenv("REMOTE_ADDR"), "unknown")) {
     $ip = getenv("REMOTE_ADDR");
    } else
     if (isset ($_SERVER['REMOTE_ADDR']) && $_SERVER['REMOTE_ADDR'] && strcasecmp($_SERVER['REMOTE_ADDR'], "unknown")) {
      $ip = $_SERVER['REMOTE_ADDR'];
     } else {
      $ip = "unknown";
     }
  return ($ip);
 }
 function inject_check($sql_str) { //防止注入
  $check = eregi('select|insert|update|delete|'|/*|*|../|./|union|into|load_file|outfile', $sql_str);
  if ($check) {
   echo "输入非法注入内容！";
   exit ();
  } else {
   return $sql_str;
  }
 }
 function checkurl() { //检查来路
  if (preg_replace("/https?://([^:/]+).*/i", "1", $_SERVER['HTTP_REFERER']) !== preg_replace("/([^:]+).*/", "1", $_SERVER['HTTP_HOST'])) {
   header("Location: http://www.111com.net");
   exit();
  }
 }
 function htmtocode($content) {
 $content = str_replace("n", "
", str_replace(" ", " ", $content));
 return $content;
}

}
$db=new mysql("localhost","root","","Messages","","gbk");
?>