这是mycode dbclass.php,我是oops概念的新手,
<?php
class Database {
private $link;
private $hostname, $username, $password, $dbname;
public function __construct( $hostname, $username, $password, $dbname ) {
$this->link=mysql_connect($this->hostname,$this->username,$this->password) or die("Mysql Connection error!!");
mysql_select_db($this->dbname,$this->link) or die("error:".mysql_error());
return true;
}
public function query( $query ) {
$result = mysql_query( $query );
if ( !$result ) {
die('Invalid query: ' . mysql_error());
}
return $result;
}
public function __destruct() {
mysql_close($this->link) or die("Error:".mysql_error());
}
}
?>
<?php
include("dbclass.php");
$db = new Database("localhost", "root", "password", "test");
$result = $db->query("select * from messages");
while ( $row = mysql_fetch_array( $result ) ) {
echo $row['id'];
}
?>
如果我运行此代码,它将显示数据库未连接。不知道为什么
最佳答案
问题在这里:
$this->link=mysql_connect($this->hostname,$this->username,$this->password)
您没有将函数中的参数分配给您的类变量。因此,这样做
$this->hostname = $hostname;
$this->username = $username;
$this->password = $password;
然后给出:
$this->link=mysql_connect($this->hostname,$this->username,$this->password);