Php 连接到数据库时未定义的变量
我不知道为什么当我尝试调用Php 连接到数据库时未定义的变量,php,oop,constructor,Php,Oop,Constructor,我不知道为什么当我尝试调用connect()方法时,user、host和password变量未定义 $app->get('/get', function () use($app){ $db = new Db_handler; $db->connect(); } ); 下面是Db\u处理程序类本身 <?php class Db_handler{ private $driver
connect()
方法时,user
、host
和password
变量未定义
$app->get('/get', function () use($app){
$db = new Db_handler;
$db->connect();
}
);
下面是Db\u处理程序
类本身
<?php
class Db_handler{
private $driver;
private $host;
private $port;
private $schema;
private $username;
private $password;
function Db_handler( $config_file = 'connection.ini' ){
if(!$connection_data = parse_ini_file($config_file, true)) throw new exception("No se puedo abrr el fichero de configuracion ".$config_file." .");
$driver = $connection_data["database"]["driver"];
$host = $connection_data["database"]["host"];
$port = $connection_data["database"]["port"];
$schema = $connection_data["database"]["schema"];
$username = $connection_data["database"]["username"];
$password = $connection_data["database"]["password"];
echo $host;
echo $username;
echo $password;
}
function connect(){
$link = mysql_connect($host, $username, $root)
or die('No se pudo conectar: ' . mysql_error());
}
}
?>
构造函数的回音正确显示变量。编辑连接函数。更改此行:
$link = mysql_connect($host, $username, $root)
为此:
$link = mysql_connect($this->host, $this->username, $this->password)
函数connect中使用的变量是未初始化的局部变量。当您将关键字$this与指针->一起使用时,您将调用构造函数中已经定义的类变量。因此,在构造函数中设置类私有变量也很重要:
$this->driver = $connection_data["database"]["driver"];
$this->host = $connection_data["database"]["host"];
$this->port = $connection_data["database"]["port"];
$this->schema = $connection_data["database"]["schema"];
$this->username = $connection_data["database"]["username"];
$this->password = $connection_data["database"]["password"];
我认为未定义的变量只有$root。 您可以调用
mysql\u connect($host,$username,$root)
并且$root不会在任何地方声明。在构造函数和
connect()
方法中,使用$this作为每个变量名称的前缀
$this->driver = ...
$this->host = ...
等等