EditableGrid - addRow函数无法正常工作

Question

我已经下载了Editable Grid，我发现它是一个非常有用的工具。目前我在向数据库添加新行时遇到问题。到目前为止，数据正从数据库中提取并显示在网格上，它还允许我更新和删除数据。当我尝试添加数据时，每次单击“添加”并弹出错误？

DatabaseGrid.prototype.addRow = function(brandId)

{
  var self = this;

        $.ajax({
        url: 'add.php',
        type: 'POST',
        dataType: "html",
        data: {
            tablename : self.editableGrid.name,
            brandName:  $("#brandName").val(),
            brandCategory:  $("#brandCategory").val(),
            brandKeyword:  $("#brandKeyword").val()
            //addedBy:  $("#addedBy").val(),
            //dateTime:  $("#dateTime").val()

        },
        success: function (response)
        {
            if (response == "ok" ) {

                // hide form
                showAddForm();
                $("#brandName").val('');
                $("#brandCategory").val('');
                $("#brandKeyword").val('');
                //$("#addedBy").val('');
                //$("#dateTime").val('');

                alert("Row added : reload model");
                self.fetchGrid();
            }
            else
              alert("error");
            console.log(message);
        },
        error: function(XMLHttpRequest, textStatus, exception) { alert("Ajax failure\n" + errortext); },
        async: true
    });
};

PHP

<?php
require_once('config.php');         

// Database connection                                   
$mysqli = mysqli_init();
$mysqli->options(MYSQLI_OPT_CONNECT_TIMEOUT, 5);
$mysqli->real_connect($config['db_host'],$config['db_user'],$config['db_password'],$config['db_name']); 

// Get all parameter provided by the javascript
$brandName = $mysqli->real_escape_string(strip_tags($_POST['brandName']));
$brandCategory = $mysqli->real_escape_string(strip_tags($_POST['brandCategory']));
$brandKeyword = $mysqli->real_escape_string(strip_tags($_POST['brandKeyword']));
//$addedBy = $mysqli->real_escape_string("kate");
//$dateTime = $mysqli->real_escape_string("CURRENT_TIMESTAMP");
$tablename = $mysqli->real_escape_string(strip_tags($_POST['tablename']));

$return=false;
if ( $stmt = $mysqli->prepare("INSERT INTO ".$tablename." (brandName, brandCategory, brandKeyword) VALUES ( ?, ?, ?)")) {

    $stmt->bind_param("ss", $brandName, $brandCategory, $brandKeyword);
    $return = $stmt->execute();
    $stmt->close();
}             
$mysqli->close();

echo $return ? "ok" : "error";

HTML

var datagrid = new DatabaseGrid();
        window.onload = function() {
            // key typed in the filter field
            $("#filter").keyup(function() {
                datagrid.editableGrid.filter( $(this).val());
                // To filter on some columns, you can set an array of column index 
                //datagrid.editableGrid.filter( $(this).val(), [0,3,5]);
              });
            $("#showaddformbutton").click( function()  {
              showAddForm();
            });
            $("#cancelbutton").click( function() {
              showAddForm();
            });
            $("#addbutton").click(function() {
              datagrid.addRow();
            });
        };
    </script>
    <!-- simple form, used to add a new row -->
    <div id="addform">
        <div class="row">
            <input type="text" id="brandName" name="brandName" placeholder="Brand Name" />
        </div>
        <div class="row">
            <select id="brandCategory" name="brandCategory">
                <option value="">Select...</option>
                <option value="Arts and Entertainment">Arts and Entertainment</option>
                <option value="Automotive">Automotive</option>
                <option value="Business">Business</option>
                <option value="Careers">Careers</option>
                <option value="Education">Education</option>
                <option value="Family and Parenting">Family and Parenting</option>
                <option value="Health and Fitness">Health and Fitness</option>
                <option value="Food and Drink">Food and Drink</option>
                <option value="Hobbies and Interests">Hobbies and Interests</option>
                <option value="Home and Garden">Home and Garden</option>
                <option value="Law, Government and Politics">Law, Government and Politics</option>
                <option value="News">News</option>
                <option value="Personal Finance">Personal Finance</option>
                <option value="Pets">Pets</option>
                <option value="Society">Society</option>
                <option value="Science">Science</option>
                <option value="Shopping">Shopping</option>
                <option value="Sports">Sports</option>
                <option value="Style and Fashion">Style and Fashion</option>
                <option value="Technology and Computing">Technology and Computing</option>
                <option value="Travel">Travel</option>
                <option value="Real Estate">Real Estate</option>
                <option value="Religion and Spirituality">Religion and Spirituality</option>
            </select>
        </div>
         <div class="row">
             <textarea name="brandKeyword" id="brandKeyword" placeholder="Add Keywords"></textarea>
        </div>
        <div class="row tright">
          <a id="addbutton" class="button green" ><i class="fa fa-save"></i> Add</a>
          <a id="cancelbutton" class="button delete">Cancel</a>
        </div>
    </div>