mysql数据库连接程序_PHP教程

豆包AI编程

豆包推出的AI编程助手

483

查看详情

mysql教程数据库教程连接程序
这里提供的数据库连接类程序，后面还提供了一个sql安全检测函数与sql语句完整性检测函数。*/

class db_mysql {  var $connid;  var $querynum = 0;  var $expires;  var $cursor = 0;  var $cache_id = '';  var $cache_file = '';  var $cache_expires = '';  var $halt = 0;  var $result = array();  function connect($dbhost, $dbuser, $dbpw, $dbname, $pconnect = 0) {   global $cfg;   $this->expires = $cfg['db_expires'];   $func = $pconnect == 1 ? 'mysql_pconnect' : 'mysql_connect';   if(!$this->connid = $func($dbhost, $dbuser, $dbpw)) {    $this->halt('can not connect to mysql server');   }   if($this->version() > '4.1' && $cfg['db_charset']) {    mysql_query("set names '".$cfg['db_charset']."'" , $this->connid);   }   if($this->version() > '5.0') {    mysql_query("set sql_mode=''" , $this->connid);   }   if($dbname) {    if(!mysql_select_db($dbname , $this->connid)) {     $this->halt('cannot use database '.$dbname);    }   }   return $this->connid;  }  function select_db($dbname) {   return mysql_select_db($dbname , $this->connid);  }  function query($sql , $type = '', $expires = 0, $save_id = false) {         $sql=checksql($sql);   if($type == 'cache' && stristr($sql, 'select')) {    $this->cursor = 0;    $this->cache_id = md5($sql);    $this->result = array();    $this->cache_expires = $expires ? $expires + mt_rand(-9, 9) : $this->expires;    return $this->_query($sql);   }   if(!$save_id) $this->cache_id = 0;   $func = $type == 'unbuffered' ? 'mysql_unbuffered_query' : 'mysql_query';   if(!($query = $func($sql , $this->connid)) && $this->halt) {    $this->halt('mysql query error', $sql);   }   $this->querynum++;   return $query;  }  function get_one($sql, $type = '', $expires = 0) {   $query = $this->query($sql, $type, $expires);   $r = $this->fetch_array($query);   $this->free_result($query);   return $r ;  }    function counter($table, $condition = '', $type = '', $expires = 0) {   global $cfg;   $table = strpos($table, $cfg['tb_pre']) === false ? $cfg['tb_pre'].$table : $table;   $sql = "select count(*) as num from {$table}";   if($condition) $sql .= " where $condition";   $r = $this->get_one($sql, $type, $expires);   return $r ? $r['num'] : 0;  }  function fetch_array($query, $result_type = mysql_assoc) {   return $this->cache_id ? $this->_fetch_array($query) : @mysql_fetch_array($query, $result_type);  }  function affected_rows() {   return mysql_affected_rows($this->connid);  }  function num_rows($query) {   return mysql_num_rows($query);  }  function num_fields($query) {   return mysql_num_fields($query);  }  function escape_string($str){   return mysql_escape_string($str);  }  function result($query, $row) {   return @mysql_result($query, $row);  }  function free_result($query) {   return @mysql_free_result($query);  }  function insert_id() {   return mysql_insert_id($this->connid);  }  function fetch_row($query) {   return mysql_fetch_row($query);  }  function version() {   return mysql_get_server_info($this->connid);  }  function close() {   return mysql_close($this->connid);  }  function error() {   return @mysql_error($this->connid);  }  function errno() {   return intval(@mysql_errno($this->connid)) ;  }  function halt($message = '', $sql = '') {   global $cfg;   if($message) {    if($cfg['errlog']) {     $log = "query:$sql|errno:".$this->errno()."|error:".$this->error()."|errmsg:$message";     log_write($log, 'sql');    }   }         showmsg("mysqlerror:$message",'-1');         exit();  }  function _query($sql) {   global $fr_time;   $this->cache_file = cache_root.'/sql/'.substr($this->cache_id, 0, 2).'/'.$this->cache_id.'.php教程';   if(!is_file($this->cache_file) || ($fr_time - @filemtime($this->cache_file) > $this->cache_expires)) {    $tmp = array();    $result = $this->query($sql, '', '', true);    while($r = mysql_fetch_array($result, mysql_assoc)) {     $tmp[] = $r;    }    $this->result = $tmp;    $this->free_result($result);    file_put($this->cache_file, "");   } else {       $this->result = include $this->cache_file;   }   return $this->result;  }  function _fetch_array($query = array()) {   if($query) $this->result = $query;   if(isset($this->result[$this->cursor])) {    return $this->result[$this->cursor++];   } else {    $this->cursor = $this->cache_id = 0;    return array();   }  } } function checksql($dbstr,$querytype='select'){  $clean = '';  $old_pos = 0;  $pos = -1;  //普通语句，直接过滤特殊语法  if($querytype=='select'){   $nastr = "/[^0-9a-z@._-]{1,}(union|sleep|benchmark|load_file|outfile)[^0-9a-z@.-]{1,}/i";   if(preg_match($nastr,$dbstr)){             log_write($dbstr,'sql');             showmsg('safeerror:10001', '网页特效:;');             exit();   }  }  //完整的sql检查  while (true){   $pos = strpos($dbstr, ''', $pos + 1);   if ($pos === false){    break;   }   $clean .= substr($dbstr, $old_pos, $pos - $old_pos);   while (true){    $pos1 = strpos($dbstr, ''', $pos + 1);    $pos2 = strpos($dbstr, '', $pos + 1);    if ($pos1 === false){     break;    }    elseif ($pos2 == false || $pos2 > $pos1){     $pos = $pos1;     break;    }    $pos = $pos2 + 1;   }   $clean .= '$s$';   $old_pos = $pos + 1;  }  $clean .= substr($dbstr, $old_pos);  $clean = trim(strtolower(preg_replace(array('~s+~s' ), array(' '), $clean)));  if (strpos($clean, 'union') !== false && preg_match('~(^|[^a-z])union($|[^[a-z])~s', $clean) != 0){   $fail = true;  }  elseif (strpos($clean, '/*') > 2 || strpos($clean, '--') !== false || strpos($clean, '#') !== false){   $fail = true;  }  elseif (strpos($clean, 'sleep') !== false && preg_match('~(^|[^a-z])sleep($|[^[a-z])~s', $clean) != 0){   $fail = true;  }  elseif (strpos($clean, 'benchmark') !== false && preg_match('~(^|[^a-z])benchmark($|[^[a-z])~s', $clean) != 0){   $fail = true;  }  elseif (strpos($clean, 'load_file') !== false && preg_match('~(^|[^a-z])load_file($|[^[a-z])~s', $clean) != 0){   $fail = true;  }  elseif (strpos($clean, 'into outfile') !== false && preg_match('~(^|[^a-z])intos+outfile($|[^[a-z])~s', $clean) != 0){   $fail = true;  }  elseif (preg_match('~([^)]*?select~s', $clean) != 0){   $fail = true;  }  if (!empty($fail)){         log_write($dbstr,'sql');         showmsg('safeerror:10002', 'javascript:;');exit;  }  else  {   return $dbstr;  } }