一对夫妇的提示PHP中实现面向对象编程的时候，你应该做的：
1）我想可能重新考虑不直接烘烤数据库凭据到类，就更难/更麻烦，如果要修改它们通过UI你想实现一个UI控制机制。相反，请尝试制作一个define或者一个json pref文件或一个包含数组的类似动态创建的php文件。我会做一个定义，因为它是最简单的证明：
/config.php
# You can create a series of defines including the database
define('DB_HOST','localhost');
define('DB_NAME','dbname');
define('DB_USER','root');
define('DB_PASS','dbpassword');
# To maximize compatibility it's helpful to define fwd/back slash
define('DS',DIRECTORY_SEPARATOR);
# It is helpful to create path defines for easy file inclusion
define('ROOT_DIR',__DIR__);
define('CLASSES',ROOT_DIR.DS.'classes');
# Start session
session_start();
2）config.php文件，然后让你不必手动包括创建一个类autoloader /需要页面中的类。它会自动它们包括：
spl_autoload_register(function($class) {
if(class_exists($class))
return;
# This will turn a namespace/class into a path so should turn:
# $db = new \DBUtility\DBHelper();
# into:
# /var/www/domain/httpdocs/classes/DBUtility/DBHelper.php
$path = str_replace(DS.DS,DS,CLASSES.DS.str_replace('\\',DS,$class).'.php');
# If the class file is located in the class folder, it will include it
if(is_file($path))
include_once($path);
});
3）我要建立一个静态连接，所以你不创建一个新的连接每一次（也是我会用PDO）：
/班/ DBUtility/DBHelper。PHP
<?php
namespace DBUtility;
class DBHelper
{
protected $query;
private static $con;
public function connection()
{
# This will send back the connection without making a new one
if(self::$con instanceof \PDO)
return self::$con;
# I like to catch any pdo exceptions on connection, just incase.
try {
# Assign the connection
self::$con = new \PDO('mysql:host='.DB_HOST.';dbname='.DB_NAME,DB_USER,DB_PASS);
}
catch(\PDOException $e) {
# Here you can just die with a more user-friendly error.
# It would be helpful to save the actual error to a log file
$msg = $e->getMessage();
# I would put your log outside the root or in a protected folder
$txt = realpath(ROOT_DIR.DS.'..').DS.'errors'.DS.'sql.txt';
# Make a directory if none set
if(!is_dir(pathinfo($txt,PATHINFO_DIRNAME))) {
# Make the directory
if(mkdir(pathinfo($txt,PATHINFO_DIRNAME),0744,true)) {
# Save to log file
file_put_contents($txt,$msg.PHP_EOL);
}
}
else {
# Save to log file
file_put_contents($txt,$msg.PHP_EOL);
}
die("Site is under maintenance.");
}
}
# It would be helpful to create a query that will bind and not bind
public function query($sql,$bind = false)
{
if(is_array($bind)) {
foreach($bind as $key => $value) {
$sKey = ":{$key}";
$bindArr[$sKey] = $value;
}
$this->query = $this->connection()->prepare($sql);
$this->query->execute($bindArr);
}
else {
# The second "query" on this is the method from PDO, not the
# "query" method from this class
$this->query = $this->connection()->query($sql);
}
return $this;
}
public function getResults()
{
if(empty($this->query))
return false;
while($result = $this->query->fetch(\PDO::FETCH_ASSOC)) {
$row[] = $result;
}
return (isset($row))? $row : false;
}
}
# If your page ends with a php tag, you should just remove it. It will
# protect against empty spaces that may cause "header already sent" errors
3a）的我使用类似于此自动装载功能的东西：
/classes/Helper.php
class Helper
{
public static function autoload($function)
{
if(function_exists($function))
return;
$path = ROOT_DIR.DS.'functions'.DS.$function.'.php';
if(is_file($path))
include_once($path);
}
}
4）创建有用/可重复使用的功能或类/方法
/functions/getUserRole.php
function getUserRole($username,$password,\DBUtility\DBHelper $DBHelper)
{
return $DBHelper->query('CALL getUserRoleByLogin(:0, :1)',array($username,$password))->getResults();
}
的index.php
# Include the config file
require_once(__DIR__.DIRECTORY_SEPARATOR.'config.php');
if (isset($_POST['submit'])) {
# No need for this line ->> include "/DBUtility/DBHelper.php";
# Use trim to remove empty spaces on the left and right
$username = trim($_POST['username']);
$password = trim($_POST['password']);
}
if (empty($username) || empty($password)) {
echo "Fill out the fields!";
} else {
# User our function autoloader to include this function
Helper::autoload('getUserRole');
# Use the function and inject the DB class
$userRoles = getUserRole($username,$password,new \DBUtility\DBHelper());
$count = count($userRoles);
echo "Count: {$count}";
echo '<pre>';
print_r($userRoles);
echo '</pre>';
}
嗯，你是正确的做'require_once'或'include_once'。它是否说你不能声明“DBHelper”或什么是类名？ – Rasclatt
@Rasclatt首先，谢谢。是的，我得到了错误致命错误：无法重新声明类DBHelper – p3ace
其他原因可能是1）您正在使用相同的名称作为已在其他地方创建的类（可能由别人），在这种情况下，您应该使用命名空间2）也许你重复这个文件，以重命名和扩展它，并忘记更改重复文件上的类名称。 – Rasclatt