PHP - Expect Paramenter

我一直在尋找這個錯誤的天，我不能找到錯誤。PHP - Expect Paramenter

我知道在數據庫中放置日誌信息不是標準做法。我通常會使用include。當我發現錯誤時我會改變。

確切的錯誤是： 警告：mysqli_error（）期望的是1個參數，0在/home/mjcrawle/class/database.class.php給定線27對不起無法連接：

我有評論//這是錯誤

我的數據庫文件的確切位置線26 ...

<?php 

// Database Class 
    class Database { 
     /* Attributes */ 
     private $host = 'localhost'; 
     private $database = 'xxxxxxxxxxxxxx'; 
     private $username = 'xxxxxxxxxxx'; 
     private $password = 'xxxxxxxxxx'; 
     public $connection; 

     /*Connection functions*/ 
     function __construct(){ 
      $this->db_connect(); 
     } //ends constructor 

     /*Destructor function*/ 
     function __destruct() { 
     } //ends destructor 

     public function db_connect() { 

      /*Connection to the DB*/ 
      $conn = mysqli_connect($this->host, $this->username, $this->password) 
        or die("Sorry unable to connect: " . mysqli_error()); //Connects to server

/這是行26/

mysqli_select_db($conn, $this->database) 
         or die("Sorry unable to connect: " . mysqli_error()); //Connect to database 

      $this->connection = $conn; 
     } 

     /*Query the database*/ 
     public function db_query($query){ 


     $result = mysqli_query($this->connection, $query); 

     return $result; 
     } 

    } //End database class 


?>

來源

2012-04-04 Michael Crawley