error message

when i run my code i get the could not add project message cannot figure out why?

<?php require 'inc/functions.php';

$pageTitle = "Task | Time Tracker"; $page = "tasks"; $project_id = $title = $date = $time = "";

if ($_SERVER['REQUEST_METHOD'] == 'POST') { $project_id = trim(filter_input(INPUT_POST, 'project_id', FILTER_SANITIZE_NUMBER_INT)); $title = trim(filter_input(INPUT_POST, 'title', FILTER_SANITIZE_STRING)); $date = trim(filter_input(INPUT_POST, 'date', FILTER_SANITIZE_STRING)); $time = trim(filter_input(INPUT_POST, 'time', FILTER_SANITIZE_NUMBER_INT));

if(empty($project_id) || empty($title) || empty($date) || empty($time)){ $error_message = "please fill in the required fields : Project, Title, Date, Time"; } else {

if (add_task($project_id, $title, $date, $time)) {
  header('Location: task_list.php');
  exit;

} else{ $error_message = "could not add task"; }

} }

include 'inc/header.php'; ?>

<div class="section page"> <div class="col-container page-container"> <div class="col col-70-md col-60-lg col-center"> <h1 class="actions-header">Add Task</h1> <?php if(isset($error_message)) { echo "<p class='message'>$error_message</p>"; } ?> <form class="form-container form-add" method="post" action="task.php"> <table> <tr> <th> <label for="project_id">Project</label> </th> <td> <select name="project_id" id="project_id"> <option value="">Select One</option> <?php foreach(get_project_list() as $item){ echo "<option value='" . $item['project_id'] . "'";

                      if($project_id == $item['project_id']) {
                        echo 'selected';
                      }
                      echo ">" .  $item['title'] . "</option>";

                    }
                    ?>
                        </select>
                    </td>
                </tr>
                <tr>
                    <th><label for="title">Title<span class="required">*</span></label></th>
                    <td><input type="text" id="title" name="title" value="<?php echo htmlspecialchars($title);?>" /></td>
                </tr>
                <tr>
                    <th><label for="date">Date<span class="required">*</span></label></th>
                    <td><input type="text" id="date" name="date" value="<?php echo htmlspecialchars($date);?>" placeholder="mm/dd/yyyy" /></td>
                </tr>
                <tr>
                    <th><label for="time">Time<span class="required">*</span></label></th>
                    <td><input type="text" id="time" name="time" value="<?php echo htmlspecialchars($time);?>" /> minutes</td>
                </tr>
            </table>
            <input class="button button--primary button--topic-php" type="submit" value="Submit" />
        </form>
    </div>
</div>

</div>

<?php include "inc/footer.php"; ?>

functions.php:

<?php //application functions

function get_project_list() { include"connection.php";

try{ return $db->query('SELECT project_id, title, category FROM projects'); } catch(Exception $e){ echo "Error!: ". $e->getMessage() . "<br>"; return array(); } }

function get_task_list() { include"connection.php";

$sql = 'SELECT tasks. *, projects.title as project FROM tasks' .' JOIN projects ON tasks.project_id = projects.project_id';

try{ return $db->query($sql); return $db->query($sql); } catch(Exception $e){ echo "Error!: ". $e->getMessage() . "<br>"; return array(); } }

function add_project($title,$category){ include('connection.php');

$sql = 'INSERT INTO projects(title, category) VALUES (?,?)';

try{ $results = $db->prepare($sql); $results->bindvalue(1, $title, PDO::PARAM_STR); $results->bindValue(2, $category, PDO::PARAM_STR); $results->execute();

} catch (Exception $e) { echo "Error!: " . $e->getMessage() . "<br />"; return false;

} return true; }

function add_task($project_id,$title, $date, $time){ include('connection.php');

$sql = 'INSERT INTO tasks(project_id, title, date, time) VALUES(?,?.?,?)';

try{ $results = $db->prepare($sql); $results->bindvalue(1, $project_id, PDO::PARAM_INT); $results->bindValue(2, $title, PDO::PARAM_STR); $results->bindvalue(1, $date, PDO::PARAM_STR); $results->bindValue(2, $time, PDO::PARAM_INT); $results->execute();

} catch (Exception $e) { echo "Error!: " . $e->getMessage() . "<br />"; return false;

} return true; }