<?php

class Dbhelper0 {      
    private $host   = DB_HOST;
    private $user   = DB_USERNAME;
    private $pwd    = DB_PWD;
	private $dbname = 'qiangwan_hw';
	private $dblink;
	private static $instance;

	private function __construct() {
		// dolog('open db link');
		$obj = $this->dblink = new mysqli($this->host, $this->user, $this->pwd, $this->dbname);
		if ($obj->connect_error) {
			dolog('connect to db0 failed');
			die('connect to db failed');
		}
		$this->dblink->query("set names utf8");
	}

	public static function getinstance() {
		if (!(self::$instance instanceof self)) {
			self::$instance = new self();
		}
		return self::$instance;
	}

	public function exec_db($sql) {
		// dolog($sql);
		$rs = $this->dblink->query($sql) or die(dolog($_SERVER['QUERY_STRING']."\n".$this->dblink->error, $sql));
		return $rs;
	}

	public function exec_db_insertid($sql) {
		$rs = $this->dblink->query($sql) or die(dolog($_SERVER['QUERY_STRING']."\n".$this->dblink->error, $sql));
		return $this->dblink->insert_id;
	}

	public function getonerecord($sql) {
		// dolog($sql);
		$result = $this->dblink->query($sql) or die(dolog($_SERVER['QUERY_STRING']."\n".$this->dblink->error, $sql));
		$data   = $result->fetch_all(MYSQLI_ASSOC);
		mysqli_free_result($result);
		return $data[0];
	}

	public function close() {
		// dolog('close db link');
		if ($this->dblink) {
			mysqli_close($this->dblink);
		}
	}

	private function __clone() {}

	public function __destruct() {
		$this->close();
	}
}

?>