嗯，看到屏幕截图的问题，这里有我的代码，因为你们中的一些人需要测试代码＆＃34;。
我正在使用mysql和PDO对象的项目中工作。一切都按预期工作，直到我开始使用reports.php，我需要使用functions.php中的两个函数，问题是，它显示错误，因为我的数据库常量已经定义。我知道它正在发生，因为我在每个需要它的函数中都包含一个名为db_connection.php的外部连接文件。
我试图将每个函数中的include更改为include_once或require_once，但是，它会显示一个错误，说明$ conn变量（它是我的连接的调用方式）未定义，而execute（），还没有定义数据库语句的prepare（），query（）方法。
我还试图将db_connection.php文件中的代码包含到函数中，将它放在我的functions.php的开头，然后分配给我的$ conn变量，即刚刚创建的函数。
有谁知道如何使用PDO声明我的数据库连接，而不是两次声明它？
谢谢，我希望，代码能让一切变得更清晰......因为它不适合我......
CSS
.required {
&:after {
content: " *";
color: red;
}
}
.addLink {
color: #645180;
margin-bottom: 10px;
display: block;
}
.submit {
border: 0;
background-color: #645180;
color: white;
width:100%;
margin: 15px 0;
padding:5px;
}
#content {
padding: 3% 0;
h1 {
text-align:center;
}
}
ul.projectList,
ul.taskList {
list-style: none;
border: .5em solid white;
padding:15px 0;
li {
background-color: white;
border-bottom: 1px solid #b2b2b2;
padding: 5 15px;
&:last-child {
border-bottom: 0;
}
}
}
table {
width: 40%;
margin:0 auto;
td {
padding: .2rem .2rem;
}
}
thead > tr> td {
font-weight: bold;
background-color: #cebece;
}
.totalReportTime > th {
background-color: #632c62;
color: white;
}
db_connection.php
<?php
define('DB_SERVER', "localhost");
define('DB_USER', "tracker_userr");
define('DB_PASSWORD', "tracker_passs");
define('DB_DATABASE', "tracker");
define('DB_DRIVER', "mysql");
?>
的functions.php
<?php
function connect_to_db() {
define('DB_SERVER', "localhost");
define('DB_USER', "tracker_user");
define('DB_PASSWORD', "tracker_pass");
define('DB_DATABASE', "tracker");
define('DB_DRIVER', "mysql");
try {
$conn = new PDO(DB_DRIVER . ":dbname=" . DB_DATABASE . ";host=" . DB_SERVER, DB_USER, DB_PASSWORD);
$conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
//echo "Connected successfully";
} catch(PDOException $e) {
echo "Connection failed: " . $e->getMessage();
}
return $conn;
}
function get_projects_list() {
// include 'db_connection.php';
$conn = connect_to_db();
try {
return $conn->query("SELECT * FROM projects");
} catch (PDOException $e) {
echo 'Error:' . $e->getMessage() . "<br />";
return array();
}
}
function get_tasks_list($filter = null) {
// include 'db_connection.php';
$conn = connect_to_db();
$sql = 'SELECT tasks.*, projects.title as project FROM tasks'
. ' JOIN projects ON tasks.project_id = projects.project_id';
$orderBy = ' ORDER BY date DESC';
if ($filter) {
$orderBy = ' ORDER BY projects.title ASC, date DESC';
}
try {
$results = $conn->prepare($sql . $orderBy);
$results->execute();
} catch (PDOException $e) {
echo 'Error:' . $e->getMessage() . "<br />";
return array();
}
return $results->fetchAll(PDO::FETCH_ASSOC);
}
function add_project($title, $category) {
// include 'db_connection.php';
$conn = connect_to_db();
try {
$sql = "INSERT INTO projects(title, category) VALUES (:title, :category)";
$results = $conn->prepare($sql);
$results->bindParam(':title', $title, PDO::PARAM_STR, 100);
$results->bindParam(':category', $category, PDO::PARAM_STR, 100);
if($results->execute()) {
echo '1 row has been inserted';
}
$conn = null;
} catch(PDOException $e) {
echo 'Error: ' . $e->getMessage() . '<br />';
return false;
}
return true;
}
function add_task($title, $date, $time, $project_id) {
// include 'db_connection.php';
$conn = connect_to_db();
try {
$sql = "INSERT INTO tasks(title, date, time, project_id) VALUES (:title, :date, :time, :project_id)";
$results = $conn->prepare($sql);
$results->bindParam(':title', $title, PDO::PARAM_STR, 100);
$results->bindParam(':date', $date, PDO::PARAM_STR, 100);
$results->bindParam(':time', $time, PDO::PARAM_STR, 100);
$results->bindParam(':project_id', $project_id, PDO::PARAM_INT);
if($results->execute()) {
echo '1 row has been inserted';
}
$conn = null;
} catch(PDOException $e) {
echo 'Error: ' . $e->getMessage() . '<br />';
return false;
}
return true;
}
try {
$conn = new PDO(DB_DRIVER . ":dbname=" . DB_DATABASE . ";host=" . DB_SERVER, DB_USER, DB_PASSWORD);
$conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
//echo "Connected successfully";
} catch(PDOException $e) {
echo "Connection failed: " . $e->getMessage();
}
project_list.php
<?php
$pageTitle = "Project | Time Tracker";
$page = 'projects';
include('includes/functions.php');
include 'includes/header.php'; ?>
<div class="col-container">
<h1>Project List</h1>
<a class="addLink" href="project.php">Add project</a>
<ul class="projectList">
<?php
foreach (get_projects_list() as $item) {
echo '<li>' . $item['title'] . '</li>';
}
?>
</ul>
</div>
<?php include 'includes/footer.php';
的header.php
<!DOCTYPE html>
<html lang="en">
<head>
<title><?php echo $pageTitle; ?></title>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=Edge">
<meta name="description" content="project list">
<meta name="keywords" content="">
<meta name="author" content="Evelia Molina">
<meta name="viewport" content="width=device-width, initial-scale=1">
<link href='https://fonts.googleapis.com/css?family=Roboto+Slab:400,700' rel='stylesheet' type='text/css'>
<link rel="stylesheet" href="css/pre_style.css" type="text/css">
<link href="css/style.css" rel="stylesheet" type="text/css"/>
</head>
<body>
<svg style="display: none;">
<defs>
<svg id="logo_icon" viewBox="0 0 64 64" preserveAspectRatio="xMinYMin meet">
<rect x="19.5" y="41.4" transform="matrix(0.7071 -0.7071 0.7071 0.7071 -24.2442 27.4475)" width="3" height="3.3"/>
<rect x="19.4" y="19.5" transform="matrix(0.7071 -0.7071 0.7071 0.7071 -8.7041 21.0111)" width="3.3" height="3"/>
<rect x="15" y="30.4" width="3" height="3.3"/>
<rect x="30.4" y="46.1" width="3.3" height="3"/>
<path d="M32,0C14.3,0,0,14.3,0,32c0,17.7,14.3,32,32,32s32-14.3,32-32C64,14.3,49.7,0,32,0z M32,55.6C19,55.6,8.4,45,8.4,32
C8.4,19,19,8.4,32,8.4S55.6,19,55.6,32C55.6,45,45,55.6,32,55.6z"/>
<path d="M48.9,30.4c0-0.2,0-0.4-0.1-0.6c0-0.2-0.1-0.4-0.1-0.6c-0.1-0.3-0.1-0.7-0.2-1c0-0.1-0.1-0.2-0.1-0.3
c-0.4-1.6-1-3.2-1.9-4.6c-0.2-0.4-0.5-0.7-0.7-1.1c0,0-0.1-0.1-0.1-0.1c-0.3-0.4-0.6-0.8-1-1.2c0,0,0,0,0,0c0,0-0.1-0.1-0.1-0.1
c-0.4-0.4-0.8-0.8-1.2-1.2c-0.1-0.1-0.3-0.3-0.5-0.4c-0.3-0.3-0.6-0.5-0.9-0.7c-0.2-0.2-0.4-0.3-0.7-0.5c-0.3-0.2-0.5-0.3-0.8-0.5
c-0.3-0.2-0.5-0.3-0.8-0.5c-0.1-0.1-0.2-0.1-0.3-0.2c-0.1-0.1-0.3-0.1-0.4-0.2c-0.2-0.1-0.4-0.2-0.6-0.3c0,0,0,0,0,0
C36.4,15.4,34.2,15,32,15c0,7,0,11.1,0,13.5c-0.6,0-1.2,0.2-1.8,0.5c0,0-0.1,0-0.1,0c-0.1,0.1-0.2,0.1-0.2,0.2
c-0.1,0-0.1,0.1-0.2,0.1c0,0,0,0-0.1,0c0,0,0,0,0,0c-0.3,0.3-0.6,0.7-0.8,1.1c-0.9,1.8-0.1,3.9,1.6,4.7c1.1,0.5,2.3,0.5,3.3-0.1
c0,0,0.1,0,0.1,0c0.1-0.1,0.2-0.1,0.2-0.2c0.1,0,0.1-0.1,0.2-0.1c0,0,0,0,0.1,0c0,0,0,0,0,0l0,0c0,0,0,0,0,0
c3.8,4.3,7.2,8.2,8.9,10.1c1.7-1.5,3.1-3.3,4-5.2c0,0,0,0,0,0c0,0,0,0,0,0c0.2-0.5,0.4-0.9,0.6-1.4c0-0.1,0-0.1,0.1-0.2
c0.1-0.4,0.3-0.8,0.4-1.2c0.5-1.7,0.7-3.3,0.7-5c0-0.1,0-0.2,0-0.3C49,31.1,49,30.7,48.9,30.4z"/>
</svg>
<svg id="task_icon" viewBox="0 0 64 64" preserveAspectRatio="xMinYMin meet">
<path d="M64,53.3l-10,9.6c-0.7,0.7-1.8,1.1-2.5,1.1l0,0l0,0c-1.1,0-1.8-0.4-2.5-1.1l-10-9.6l0,0l0,0l0,0l0,0V3.6c0-2.1,1.4-3.6,3.6-3.6h17.8C62.6,0,64,1.4,64,3.6V53.3L64,53.3L64,53.3z M56.9,7.1H46.2v7.1h10.7V7.1z M56.9,49.1V17.8H46.2v31.3l5.3,4.3l0,0L56.9,49.1z M21.3,64H3.6C1.4,64,0,62.6,0,60.4V3.6C0,1.4,1.4,0,3.6,0h17.8c2.1,0,3.6,1.4,3.6,3.6v56.9C24.9,62.6,23.5,64,21.3,64z M17.8,7.1H7.1v7.1h5.3c1.1,0,1.8,0.7,1.8,1.8s-0.7,1.8-1.8,1.8H7.1v7.1h1.8c1.1,0,1.8,0.7,1.8,1.8s-0.7,1.8-1.8,1.8H7.1v7.1h5.3c1.1,0,1.8,0.7,1.8,1.8c0,1.1-0.7,1.8-1.8,1.8H7.1v7.1h1.8c1.1,0,1.8,0.7,1.8,1.8s-0.7,1.8-1.8,1.8H7.1v7.1h10.7V7.1z"/>
</svg>
<svg id="project_icon" viewBox="0 0 64 64" preserveAspectRatio="xMinYMin meet">
<path d="M60.4,64H3.6C1.4,64,0,62.6,0,60.4V3.6C0,1.4,1.4,0,3.6,0h24.9c1.4,0,2.5,0.7,3.2,2.1l5.7,12.1h23.1c2.1,0,3.6,1.4,3.6,3.6v42.7C64,62.6,62.6,64,60.4,64z M7.1,56.9h49.8V21.3h-22c-1.4,0-2.5-0.7-3.2-2.1L26.3,7.1H7.1V56.9z"/>
<path d="M60.4,7.1h-16c-2.1,0-3.6-1.4-3.6-3.6S42.3,0,44.4,0h16C62.6,0,64,1.4,64,3.6S62.6,7.1,60.4,7.1z"/>
</svg>
<svg id="report_icon" viewBox="0 0 64 64" preserveAspectRatio="xMinYMin meet">
<path d="M60.4,0H3.6C1.4,0,0,1.4,0,3.6v56.9C0,62.6,1.4,64,3.6,64h56.9c2.1,0,3.6-1.4,3.6-3.6V3.6C64,1.4,62.6,0,60.4,0zM56.9,56.9H7.1V7.1h49.8V56.9z"/>
<path d="M16.5,21.3h30.9c2.1,0,3.6-1.4,3.6-3.6c0-2.1-1.4-3.6-3.6-3.6H16.5c-2.1,0-3.6,1.4-3.6,3.6C13,19.9,14.4,21.3,16.5,21.3z" />
<path d="M16.5,35.6h30.9c2.1,0,3.6-1.4,3.6-3.6s-1.4-3.6-3.6-3.6H16.5c-2.1,0-3.6,1.4-3.6,3.6S14.4,35.6,16.5,35.6z"/>
<path d="M16.5,49.8h30.9c2.1,0,3.6-1.4,3.6-3.6s-1.4-3.6-3.6-3.6H16.5c-2.1,0-3.6,1.4-3.6,3.6S14.4,49.8,16.5,49.8z"/>
</svg>
</defs>
</svg>
<header class="header">
<div class="col-container">
<h1>
<a class="logo" href="./">
<svg viewbox="0 0 64 64" class="logo-icon"><use xlink:href="#logo_icon"></use></svg>
<span class="logo-name">Time Tracker</span>
</a>
</h1>
<ul class="nav">
<li class="nav-item tasks<?php if ($page == "tasks") { echo " on"; } ?>"><a class="nav-link" href="task_list.php">Tasks</a></li>
<li class="nav-item projects<?php if ($page == "projects") { echo " on"; } ?>"><a class="nav-link" href="project_list.php">Projects</a></li>
<li class="nav-item reports<?php if ($page == "reports") { echo " on"; } ?>"><a class="nav-link" href="reports.php">Reports</a></li>
</ul>
</div>
</header>
<div id="content">
footer.php
</div><!-- end content -->
<footer class="footer">
<div class="col-container">
<svg viewbox="0 0 64 64" class="logo-icon"><use xlink:href="#logo_icon"></use></svg>
<p class="footer-copy">© <?php echo date("Y"); ?> Time Tracker by Eve</p>
</div>
</footer>
</body>
</html>
project.php
<?php require 'includes/functions.php';
$pageTitle = "Project | Time Tracker";
$page = 'projects';
if ($_SERVER['REQUEST_METHOD'] == 'POST') {
$title = filter_input(INPUT_POST, 'title', FILTER_SANITIZE_STRING);
$category = filter_input(INPUT_POST, 'category', FILTER_SANITIZE_STRING);
if(empty($title) || empty($category)) {
$error_message = "Title and category can not be empty";
} else {
if(add_project($title, $category)) {
header('Location: project_list.php');
exit;
} else {
$error_message = "Could not add project";
}
}
}
include 'includes/header.php';?>
<div class="col-container">
<h1>Add project</h1>
<?php
if (isset($error_message)) {
echo '<p class="message">' . $error_message . '</p>';
}
?>
<form method="POST" action="project.php">
<div>
<label for="title" class="required">Title</label>
<input name="title" id="title" type="text" value="" />
</div>
<div>
<label for="category" class="required">Category</label>
<select id="category" name="category">
<option value="">Select one</option>
<option value="Charity">charity</option>
<option value="Science">science</option>
<option value="Art">art</option>
</select>
</div>
<button class="submit" type="submit" name="submit">Submit</button>
</form>
</div>
<?php include 'includes/footer.php';
task.php
<?php require 'includes/functions.php';
$pageTitle = "Task | Time Tracker";
$page = 'tasks';
$project_id = $title = $date = $time = '';
if ($_SERVER['REQUEST_METHOD'] == 'POST') {
$project_id = filter_input(INPUT_POST, 'project_id', FILTER_SANITIZE_NUMBER_INT);
$title = filter_input(INPUT_POST, 'title', FILTER_SANITIZE_STRING);
$date = filter_input(INPUT_POST, 'date', FILTER_SANITIZE_STRING);
$time = filter_input(INPUT_POST, 'time', FILTER_SANITIZE_STRING);
$dateMatch = explode('/', $date);
if(empty($project_id) || empty($title) || empty($date) || empty($time)) {
$error_message = "Required fields can not be empty";
} elseif (count($dateMatch) != 3
|| strlen($dateMatch[0]) != 2
|| strlen($dateMatch[1]) != 2
|| strlen($dateMatch[2]) != 4
|| !checkdate($dateMatch[1], $dateMatch[0], $dateMatch[2])
) {
$error_message = "Please, introduce a valid date format";
} else {
if(add_task($title, $date, $time, $project_id)) {
header('Location: task_list.php');
exit;
} else {
$error_message = "Could not add task";
}
}
}
include 'includes/header.php';?>
<div class="col-container">
<h1>Add task</h1>
<?php
if (isset($error_message)) {
echo '<p class="message">' . $error_message . '</p>';
}
?>
<form method="POST" action="task.php">
<div>
<label for="project_id" class="required">Project</label>
<select name="project_id">
<option value="">Select one</option>
<?php foreach (get_projects_list() as $item) {
echo '<option value="' . $item['project_id'] . '"';
if ($project_id == $item['project_id']) {
echo 'selected';
}
echo '>' . $item['title'] . "</option>";
} ?>
</select>
</div>
<div>
<label for="title" class="required">Title</label>
<input name="title" type="text" value="<?php echo htmlspecialchars($title); ?>" />
</div>
<div>
<label for="date" class="required">Date</label>
<input name="date" type="text" value="<?php echo htmlspecialchars($date); ?>" />
</div>
<div>
<label for="time" class="required">Time</label>
<input name="time" type="text" value="<?php echo htmlspecialchars($time); ?>" />
</div>
<button class="submit" type="submit" name="submit">Submit</button>
</form>
</div>
<?php include 'includes/footer.php';
task_list.php
<?php
$pageTitle = "Task | Time Tracker";
$page = 'taks';
include('includes/functions.php');
include 'includes/header.php'; ?>
<div class="col-container">
<h1>Task List</h1>
<a class="addLink" href="task.php">Add task</a>
<ul class="taskList">
<?php
foreach (get_tasks_list() as $item) {
echo '<li>' . $item['title'] .' - In project: ' . $item['project'] . '</li>';
}
?>
</ul>
</div>
<?php include 'includes/footer.php';
reports.php
<?php require_once 'includes/functions.php';
$pageTitle = "Reports | Time Tracker";
$page = 'reports';
$filter = 'all';
include 'includes/header.php';?>
<div class="col-container">
<h1>Reports</h1>
<form method="GET" action="reports.php">
<label for="filter-by-project">Filter:</label>
<select name="filter-by-project">
<option value="">Select a project</option>
<?php
foreach(get_projects_list() as $item) {
echo '<option value="' . $item['project_id'] . '">' . $item['title'] . '</option>';
}
?>
</select>
<input class="button" type="submit" value="Run" />
</form>
<table>
<?php
$total = $project_id = $project_total = 0;
$tasks = get_tasks_list($filter);
foreach ($tasks as $item) {
if ($project_id != $item['project_id']) {
$project_id = $item['project_id'];
echo '<thead>';
echo '<tr>';
echo '<td>' . $item['project'] . '</td>';
echo '<td> Date </td>';
echo '<td> Time </td>';
echo '</tr></thead>';
}
$project_total += $item['time'];
$total += $item['time'];
echo '<tr>';
echo '<td>' . $item['title'] . '</td>';
echo '<td>' . $item['date'] . '</td>';
echo '<td>' . $item['time'] . '</td>';
echo '</tr>';
if (next($tasks)['project_id'] != $item['project_id']) {
echo '<tr>';
echo '<th colspan="2">Project Total</th>';
echo '<th>' . $project_total . '</th>';
echo '</tr>';
$project_total = 0;
}
}
?>
<tr class="totalReportTime">
<th colspan="2">Total</th>
<th><?php echo $total; ?></th>
</tr>
</table>
</div>
<?php include 'includes/footer.php';
如果我在每个函数中包含db_connection.php文件，或者如果我使用连接创建函数时出现相同的错误，则会出现错误：
Notice: Constant DB_SERVER already defined in /html/my_tracker/includes/functions.php on line 3
Notice: Constant DB_USER already defined in /html/my_tracker/includes/functions.php on line 4
Notice: Constant DB_PASSWORD already defined in /html/my_tracker/includes/functions.php on line 5
Notice: Constant DB_DATABASE already defined in /html/my_tracker/includes/functions.php on line 6
Notice: Constant DB_DRIVER already defined in /html/my_tracker/includes/functions.php on line 7
如果我需要for_once或include_once错误：
Notice: Undefined variable: conn in /html/my_tracker/includes/functions.php on line 44
Fatal error: Call to a member function prepare() on a non-object in /html/my_tracker/includes/functions.php on line 44
Fatal error: Call to a member function query() on a non-object in /html/my_tracker/includes/functions.php on line 52
Fatal error: Call to a member function execute() on a non-object in /html/my_tracker/includes/functions.php on line 66
答案 0 :(得分：2)
好的......代码很糟糕（很遗憾地说，但确实如此。数据库登录和信息永远不应该在常量中定义）。但是，这很容易修复。不要在任何地方重新定义和/或重新包含，只需在定义常量的地方执行此操作：
if (!defined('DB_SERVER')) {
define('DB_SERVER', "localhost");
}
if (!defined('DB_USER')) {
define('DB_USER', "tracker_user");
}
if (!defined('DB_PASSWORD')) {
define('DB_PASSWORD', "tracker_pass");
}
if (!defined('DB_DATABASE')) {
define('DB_DATABASE', "tracker");
}
if (!defined('DB_DRIVER')) {
define('DB_DRIVER', "mysql");
}
这应该修复讨厌的“已定义”消息，而不必重写整个代码 - 你应该这样做。
PDO应该在OOP状态下使用，而不是在程序上，并且定义$ db-class通常会阻止所有这些问题。此外，将重要信息放入已定义的常量中是一个主要的安全问题，应该避免。您应该有一些配置文件，您可以在其中定义所有这些变量，并将其加载到需要它们的类中。但是，这意味着要完全重新设计相当多的代码。