Mysql PDO - 声明数据库常量

时间：2016-10-26 16:13:43

标签： php mysql pdo include require

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"/>
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          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
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      </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"/>
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        <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">&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

1 个答案:

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。

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