简单的PDO包装器无法正常工作 [英] Simple PDO Wrapper not working
问题描述
我正在试用此包装器,无论我在index.php文件中var_dump($ row)时总是得到布尔假".
I'm trying out this Wrapper and no matter what I always just get 'boolean false' when I var_dump($row) in my index.php file.
这是我的数据库类:
<?php
// database.php
class DB {
protected $_connection = array(); // to map the connection
protected $_dbh; // property which keeps the database handler
protected $_database; // property to keep the database name
protected $_table; // property to keep the table name
protected $_query; // property to keep a query statement
public function __construct() {
// require the database configurations as an array from config.php
$this->_connection = require_once 'config.php';
// define which database driver to use (mysql?) and extract the values as
// variables
extract($this->_connection['connection']['mysql']);
// make the database and table name available to the class
$this->_database = $database;
$this->_table = $table_name;
// Check for PDO driver and create the connection to the database.
try {
$this->_dbh = new PDO($driver.":host=".$host, $username, $password);
} catch (PDOException $e) {
die ('Connection failed: ' . $e->getMessage());
}
}
public function input_query($query) {
$this->_query = $this->_dbh->prepare($query);
return $this;
}
public function execute() {
return $this->_query->execute();
}
public function single() {
$this->execute();
return $this->_query->fetch();
}
public function result_set() {
$this->execute();
return $this->fetchAll();
}
}
然后在我的index.php文件中:
And then in my index.php file:
<?php
// index.php
require_once 'database.php';
$db = new DB();
$db->input_query("SELECT `name` FROM `names` WHERE `id`=1");
$r = $db->single();
var_dump($r);
如果我愿意
<?php
// index.php
require_once 'database.php';
$db = new DB();
var_dump($db);
我得到一个对象:
object(DB)[1]
public '_connection' =>
array (size=1)
'connection' =>
array (size=4)
'sqlite' =>
array (size=3)
...
'mysql' =>
array (size=6)
...
'pgsql' =>
array (size=6)
...
'sqlsrv' =>
array (size=6)
...
protected '_dbh' =>
object(PDO)[2]
protected '_database' => string 'pagination_demo' (length=15)
protected '_table' => string 'names' (length=5)
protected '_query' => null
但是 var_dump($ r)总是返回布尔值false,有时当我用代码尝试其他操作时,我会得到'调用未定义的方法DB :: single()'或关于非对象的方法" 这类消息.
But var_dump($r) always returns boolean false and sometimes when I try different things with the code I get 'Call to an undefined method DB::single()', or 'method on a non-object' kind of message.
有人可以帮我解决这个问题吗?
Can anyone help me sort this out?
非常感谢.问候.
推荐答案
好,现在可以正常使用了.这是代码:
Ok, now it works perfectly. And here is the code:
<?php // database.php
class DB extends PDO {
protected $_connection = array(); // to map the connection
protected $_dbh; // property which keeps the database handler
protected $_database; // property to keep the database name
protected $_table; // property to keep the table name
protected $_query; // property to keep a query statement
public function __construct() {
// require the database configurations as an array from config.php
$this->_connection = require_once 'config.php';
// define which database driver to use (mysql?) and extract the values as variables
extract($this->_connection['connection']['mysql']);
// make the database and table name available to the class
$this->_database = $database;
$this->_table = $table_name;
// build the dsn string value for the PDO connection
$dsn = $driver.":host=".$host.";dbname=".$database;
// Check for PDO driver and create the connection to the database.
try {
parent::__construct($dsn, $username, $password, array(PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION));
} catch (PDOException $e) {
die ('Connection failed: ' . $e->getMessage());
}
}
public function input_query($query) {
$this->_query = parent::prepare($query);
return $this;
}
public function execute() {
return $this->_query->execute();
}
public function single() {
$this->execute();
return $this->_query->fetch();
}
public function result_set() {
$this->execute();
return $this->_query->fetchAll();
}
}
还有index.php文件:
And the index.php file:
<?php
require_once 'database.php';
$db = new DB();
$db->input_query("SELECT `name` FROM `names`");
try {
$r = $db->result_set();
} catch (PDOException $e) {
die ($e->getMessage());
}
var_dump($r);
然后var_dump($ r)给了我一大堆名字.
And var_dump($r) gave me a whole bunch of names.
非常感谢你们的帮助!
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