php的mysql数据库操作类

class dbconn { var $conn = 0; function dbconn($dbhost,$dbuser,$dbpw,$dbname){ $this->conn = mysql_connect($dbhost,$dbuser,$dbpw); !$this->conn && $this->halt("Connect to MySQL failed"); $serverinfo = mysql_get_server_info($this->conn); if ($serverinfo > '4.1' && $GLOBALS['charset']) { mysql_query("SET character_set_connection=".$GLOBALS['charset'].",character_set_results=".$GLOBALS['charset'].",character_set_client=binary",$this->conn); } if ($serverinfo > '5.0') { mysql_query("SET sql_mode=''",$this->conn); } if ($dbname && !@mysql_select_db($dbname,$this->conn)) { $this->halt('Cannot use database'); } } function select_db($dbname){ if (!@mysql_select_db($dbname,$this->conn)) { $this->halt('Cannot use database'); } } function server_info(){ return mysql_get_server_info($this->conn); } function insert_id(){ $arr = $this->fetch_array('SELECT LAST_INSERT_ID() as id'); return $arr["id"]; } function get_value($SQL,$offset=0,$field=0){ $rt = $this->fetch_all($SQL); if (isset($rt[$offset][$field])) { return $rt[$offset][$field]; } return false; } function query($SQL,$method = null,$error = true){ $query = mysql_query($SQL,$this->conn); !$query && $error && $this->halt('Query Error: '.$SQL); return $query; } function fetch_array($SQL){ $query = $this->query($SQL); return mysql_fetch_array($query); } function fetch_all($SQL) { $arr = array(); $query = $this->query($SQL); while($data = mysql_fetch_array($query)) { $arr[] = $data; } return $arr; } function affected_rows(){ return mysql_affected_rows($this->conn); } function num_rows($SQL){ $query = $this->query($SQL); if (!is_bool($query)) { return mysql_num_rows($query); } return 0; } function num_fields($SQL){ $query = $this->query($SQL); return mysql_num_fields($query); } function escape_string($str){ return mysql_escape_string($str); } function free_result(){ $void = func_get_args(); foreach ($void as $query) { if (is_resource($query) && get_resource_type($query)==='mysql result') { mysql_free_result($query); } } unset($void); } function close(){ $this->free_result(); return @mysql_close($this->conn); } function halt($msg=null){ exit($msg.'<br /><br />'.$sql.'<br /> '.mysql_error()); }}