我可以更新表，但不能在MySQLhost中插入localhost

Question

我正在使用此代码：https://github.com/husainsaify/the-cart-script-v1

我可以编辑数据库中存在的类别（演示），但我无法创建/插入新的类别/记录。

创建类别：

<?php
    require_once("inc/header.php");
    require_once("inc/navbar.php");
    require_once("../classes/Upload.php");
    // if admin is not login send him to login.php
    not_login($_SESSION['admin_id'], "login.php");
?>
<div class="container padding-10">
    <div id="search-container">
        <h1 class="text-center text-bs-primary text-upper">Add Category</h1>
        <form action="<?php echo $_SERVER['PHP_SELF'];?>" method="post" enctype="multipart/form-data">
        <?php
            if (isset($_POST['name']) && isset($_FILES['image'])) {
                $name = escape($_POST['name']);
                // check name & image is provided
                if (!empty($_POST['name']) && !empty($_FILES['image'])) {
                    $allowed = array("jpg","jpeg","png");
                    // make a new directory
                    $dir = md5(random_password().rand().$_FILES['image']['tmp_name']);
                    mkdir("../images/{$dir}/");
                    $upload = new Upload($_FILES['image'],"../images/{$dir}/", 2000000, $allowed);
                    $results = $upload->GetResult();
                    if ($results['type'] == "success") {
                        $file_name = $_FILES['image']['name'];
                        $insert = $db->Insert("category", "'','$name','images/{$dir}/$file_name'");
                        if ($insert) {
                            echo "<div class='alert alert-success'>Category has been Added</div>";
                        }else{
                            echo "<div class='alert alert-danger'>Error in adding category try again</div>";
                        }
                    }else{
                        echo "<div class='alert alert-danger'>{$results['message']}</div>";
                    }
                }else{
                    echo "<div class='alert alert-danger'>Fill In all the Fields</div>";
                }
            }
        ?>
            <div class="form-group">
                <label for="name">Name</label>
                <input type="text" class="form-control" id="name" name="name" placeholder="Enter Category Name">
            </div>
            <div class="form-group">
                <label for="image">Image</label>
                <input type="file" class="form-control" id="image" name="image">
            </div>
            <input type="submit" class="btn btn-primary" name="add" value="Add Category">
        </form>
    </div>
    <?php require_once("../inc/footer-nav.php"); ?>
</div>
<?php require_once("inc/footer.php"); ?>

更新类别：

<?php
    require_once("inc/header.php");
    require_once("inc/navbar.php");
    not_login($_SESSION['admin_id'], "login.php");
    // check $_GET['id']
    if (isset($_GET['id'])) {
        $id = escape($_GET['id']);
        // check $id is a valid category id
        $category = $db->Fetch("*","category","id='$id'");
        if(empty($category)){
            echo "<h1 class='text-center text-red'>Invalid category id</h1>";
            exit();
        }
    }else{
        echo "<h1 class='text-center text-red'>invalid url</h1>";
        exit();
    }
?>
<div class="container padding-10">
    <div id="search-container">
        <h1 class="text-center text-upper text-bs-primary">Edit `<span class='text-black'><?php echo $category['name']; ?></span>` category</h1>
        <?php
            if(isset($_POST['update'])){
                $name = escape($_POST['name']);
                if (!empty($name)) {
                    $update = $db->Update("category", "name='$name'", "id='$id'");
                    if ($update) {
                        echo "<div class='alert alert-success'>Updated Successfull <a href='category.php'>Go Back</a><</div>";
                        exit();
                    }else{
                        echo "<div class='alert alert-danger'>OOPS failed in updating name</div>";
                    }
                }else{
                    echo "<div class='alert alert-danger'>Name cannot be empty</div>";
                }
            }
        ?>
        <form action="edit_category.php?id=<?php echo $id; ?>" method="post">
            <div class="form-group">
                <label for="cname">Name</label>
                <input type="text" class="form-control" name="name" value='<?php echo $category['name']; ?>'>               
            </div>
            <div class="form-group">

                <input type="submit" value="update" name="update" class="btn btn-primary">
                <a href="edit_category_image.php?id=<?php echo $category['id']; ?>" class='btn btn-success'>Change Category Image</a>
            </div>
        </form>
    </div>
    <?php require_once("../inc/footer-nav.php"); ?>
</div>
<?php
    require_once("inc/footer.php");
?>