Javascript 后端未将书籍添加到android应用程序sql

我制作了一个电子书android应用程序，一切都很好，但是管理员时代的后端代码是用php和javascript编写的。管理员有一个功能，可以添加一本名为“savebook”的书函数不起作用，请帮助我，伙计们…每次我尝试添加一本书时，它只会显示一条失败消息，但当我通过phpmyadmin手动将书添加到数据库时，它在这里起作用的是该函数的代码 问题在于最后一个功能（我怎么想），但如果你们在代码中发现其他错误，我将不胜感激。整个网站都在运行，但这个唯一的功能不是在android平台上运行应用程序。后端使用codeigniter完成，应用程序链接到一个数据库，该数据库保存了书籍的详细信息

<?php
$this->load->view('admin/comman/header');
?>

<div class="clearfix"></div>

<div class="content-wrapper">
    <div class="container-fluid">
        <!-- Breadcrumb-->
        <div class="row pt-2 pb-2">
            <div class="col-sm-9">
                <h4 class="page-title">Add Book</h4>
                <ol class="breadcrumb">
                    <li class="breadcrumb-item"><a href="javaScript:void();">Dashboard</a></li>
                    <li class="breadcrumb-item"><a href="javaScript:void();">Books</a></li>
                    <li class="breadcrumb-item active" aria-current="page">Add Book</li>
                </ol>
            </div>
            <div class="col-sm-3">
                <div class="btn-group float-sm-right">
                    <a href="<?php echo base_url(); ?>index.php/admin/booklist" class="btn btn-outline-primary waves-effect waves-light">Books List</a>
                </div>
            </div>
        </div>
        <!-- End Breadcrumb-->
        <div class="row">
            <div class="col-lg-10 mx-auto">
                <div class="card">
                    <div class="card-body">
                        <div class="card-title">Add Book
                            <form id="edit_video_form" enctype="multipart/form-data">

                                <div class="form-group">
                                    <label for="input-1">Book Name</label>
                                    <input type="text" required value="" class="form-control" name="input_name" id="input-1">
                                </div>

                                <input type="hidden" name="id" value="">

                                <div class="form-group">
                                    <label for="input-3">Book Cost</label>
                                    <select name="select_cost" required class="form-control" id="purpose">
                                        <option value="0">Free</option>
                                        <option value="1">Paid</option>
                                    </select>
                                </div>

                                <div class="form-group" id="business" style="display:none">
                                    <label for="input-1">Book price</label>
                                    <input type="text" required value="" class="form-control" name="input_price" id="input-1" placeholder="Enter Book Price">
                                </div>

                                <div class="form-group">
                                    <label for="input-2">Book Category</label>
                                    <!-- DropDown -->
                                    <select name="select_category" required class="form-control">
                                        <option value="">Select Category</option>
                                        <?php $i = 1;
                                        foreach($categorylist as $cat) { ?>
                                            <option required value="<?php echo $cat->cat_id; ?>"><?php echo $cat->cat_name; ?></option>
                                            <?php $i++;
                                        } ?>
                                    </select>
                                </div>

                                <div class="form-group">
                                    <label for="input-2">Book Author</label>
                                    <!-- DropDown -->
                                    <select name="select_author" required class="form-control">
                                        <option value="">Select Author</option>
                                        <?php $i = 1;
                                        foreach($authorlist as $cat) { ?>
                                            <option value="<?php echo $cat->a_id; ?>"><?php echo $cat->a_title; ?></option>
                                            <?php $i++;
                                        } ?>
                                    </select>
                                </div>

                                <div class="form-group">
                                    <label for="input-1"> Book Cover Poster</label>
                                    <input type="file" required class="form-control" name="input_bookcover" id="input-1" placeholder="select Book Cover image"
                                           onchange="readURL(this,'showImage')">
                                    <input type="hidden" name="input_bookcover" value="">
                                    <p class="noteMsg">Note: Image Size must be less than 2MB.Image Height and Width less than 1000px.</p>
                                    <img id="showImage" src="<?php echo base_url() . 'assets/images/placeholder.png'; ?>" height="100" width="100" alt="your image"/>
                                </div>


                                <div class="form-group">
                                    <label for="input-1"> Upload Sample Book</label>
                                    <input type="file" required class="form-control" name="input_sample_book" id="input-1" placeholder="select Sample Book">
                                    <input type="hidden" name="input_sample_book" value="">
                                </div>

                                <div class="form-group">
                                    <label for="input-1"> Upload Full Book</label>
                                    <input type="file" required class="form-control" name="input_full_book" id="input-1" placeholder="select Full Book">
                                    <input type="hidden" name="input_full_book" value="">
                                </div>

                                <div class="form-group">
                                    <label for="input-1">Book Description</label>
                                    <textarea cols="40" rows="5" style="height: 150px" type="text" required value="" class="form-control" name="input_description"
                                              id="input-1"></textarea>
                                </div>

                                <div class="form-group">
                                    <button type="button" onclick="savebook()" class="btn btn-primary shadow-primary px-5">Save</button>
                                </div>

                            </form>
                        </div>
                    </div>


                </div>
            </div>
        </div>
    </div>

    <?php
    $this->load->view('admin/comman/footerpage');
    ?>
    <script type="text/javascript">

        $('#purpose').on('change', function () {
            if (this.value === '1') {
                $("#business").show();
            } else {
                $("#business").hide();
            }
        });

        function savebook() {

            var wallpaper_title = jQuery('input[name=wallpaper_title]').val();
            if (wallpaper_title == '') {
                toastr.error('Please enter Book Name');
                return false;
            }
            $("#dvloader").show();
            var formData = new FormData($("#edit_video_form")[0]);
            $.ajax({
                type: 'POST',
                url: '<?php echo base_url(); ?>index.php/admin/savebook',
                data: formData,
                cache: false,
                contentType: false,
                processData: false,
                dataType: "json",
                success: function (resp) {
                    $("#dvloader").hide();
                    if (resp.status == '200') {
                        document.getElementById("edit_video_form").reset();
                        toastr.success(resp.msg, 'success');
                        setTimeout(function () {
                            location.reload();
                        }, 500);
                    } else {
                        toastr.error(resp.msg);
                    }
                },
                error: function (XMLHttpRequest, textStatus, errorThrown) {
                    $("#dvloader").hide();
                    toastr.error(errorThrown.msg, 'failed');
                }
            });
        }
    </script>

enter code here

public function savebook(){
    $input_name = $_POST['input_name'];
    $input_description = $_POST['input_description'];
    $input_price = $_POST['input_price'];
    $select_category = $_POST['select_category'];
    $select_author = $_POST['select_author'];
    $select_cost = $_POST['select_cost'];
    $is_feature = "yes";
    $b_status = "enable";
    $fa_id = $_POST['select_author'];

    $input_bookcover=$this->imageupload($_FILES['input_bookcover'],'input_bookcover', FCPATH . 'assets/images/book');

    if (isset($_FILES['input_sample_book']) && !empty($_FILES['input_sample_book']['name'])) {
        $input_sample_book=$this->fileupload($_FILES['input_sample_book'],'input_sample_book', FCPATH . 'assets/images/book');
    }

    if (isset($_FILES['input_full_book']) && !empty($_FILES['input_full_book']['name'])) {
        $input_full_book=$this->fileupload($_FILES['input_full_book'],'input_full_book', FCPATH . 'assets/images/book');
    }

    $data = array(
        'b_title' => $input_name,
        'b_description' => $input_description,
        'is_paid' => $select_cost,
        'sample_b_url' => $input_sample_book,
        'b_url' => $input_full_book,
        'b_price' => $input_price,
        'fcat_id'=> $select_category,
        'b_image' => $input_bookcover,
        'is_feature' => $is_feature,
        'b_status' => $b_status,
        'fa_id' => $fa_id,
        'b_date' => date('Y-m-d h:i:s')
    );

    $res_id=$this->Adminmodel->add_book($data);

    if($res_id){
        $res=array('status'=>'200','msg'=>'Book added successfully.','id'=>$res_id);
        echo json_encode($res);exit;
    }else{
        $res=array('status'=>'400','msg'=>'fail');
        echo json_encode($res);exit;
    }
}