Обновление данных в таблице MySql

Помогите разобраться с ошибкой Notice: Undefined index: image в переменной $post_image и $post_image_tmp Что не так?

Хочу данные в полях формы, которые извлек из таблицы обновить. Как можно исправить ошибку?

if(isset($_POST['update_post'])){
    $post_author = $_POST['post_author'];
    $post_title = $_POST['post_title'];
    $post_category_id = $_POST['post_category_id'];
    $post_status = $_POST['post_status'];
    $post_image = $_FILES['image']['name'];
    $post_image_temp = $_FILES['image']['tmp_name'];
    $post_content = $_POST['post_content'];
    $post_tags = $_POST['post_tags'];

    move_uploaded_file($post_image_temp, "../images/$post_image");
    $query = "UPDATE posts SET";
    $query .= "post_title = '{$post_title}',  ";
    $query .= "post_category_id = '{$post_category_id}', ";
    $query .= "post_date = now(), ";
    $query .= "post_author = '{$post_author}',  ";
    $query .= "post_status = '{$post_status}', ";
    $query .= "post_tags = '{$post_tags}',  ";
    $query .= "post_content = '{$post_content}', ";
    $query .= "post_image = '{$post_image}'  ";
    $query .= "WHERE post_id = {$the_post_id}  ";
    $update_post = mysqli_query($connection, $query);
    // confirm($update_post);
    }

    ?>
    <form action="" method="post" enctype="multipart/form-data">
        <div class="form-group">
            <label for="title">Post Title</label>
            <input type="text" value="<?php echo $post_title; ?>" class="form-control" name="post_title">
        </div>
            <div class="form-group">
      <select name="post_category_id" id="">
        <?php
     $query = "SELECT * FROM categories";
     $select_categories = mysqli_query($connection, $query);
    //// confirm($select_categories);
    while($row = mysqli_fetch_assoc($select_categories)){
    $cat_id = $row['cat_id'];
    $cat_title = $row['cat_title'];
    echo "<option value='$cat_id'>{$cat_title}</option>";
    }
        ?>
      </select>
        </div>
            <div class="form-group">
            <label for="author">Post Author</label>
            <input type="text" value="<?php echo $post_author; ?>" class="form-control" name="post_author">
        </div>
        <div class="form-group">
            <label for="post_status">Post Status</label>
            <input value="<?php echo $post_status; ?>" type="text" class="form-control" name="post_status">
        </div>
            <div class="form-group">
            <img width="300"  src="../images/<?php echo $post_image; ?>" alt="" >
        </div>
            <div class="form-group">
            <label for="post_tags">Post Tags</label>
            <input value="<?php echo $post_tags; ?>" type="text" class="form-control" name="post_tags">
        </div>
                <div class="form-group">
            <label for="post_content">Post Content</label>
         <textarea  class="form-control" name="post_content" id="" cols="30" rows="10">
         <?php echo $post_content; ?>
         </textarea>
        </div>
        <div class="form-group">
            <input type="submit" class="btn btn-primary" name="update_post" value="Update Post">
        </div>
    </form>