codeigniter php中缺少数组数据

Question

我有从数据库获取数据的菜单 这是我的代码

<nav id="mysidebarmenu" class="amazonmenu">
<ul>
    <?php
    //Get Category array
    $categories = json_decode($this->db->get_where('ui_settings', array('type' => 'home_category'))->row()->value);

    foreach ($categories as $row) {
        ?>
        <li>
            <a href="javascript:void(0);">
                <?php
                echo $this->crud_model->get_type_name_by_id('category', $row, 'category_name');
                ?>
            </a>
            <div>
                <div class="col-md-12">
                    <?php
                    //Get Sub Category array
                    $subs = $this->db->get_where('sub_category', array('category' => $row['category_id']))->result_array();

                    foreach ($subs as $row1) {
                        $this->db->limit(4);
                        $this->db->order_by('product_id', 'desc');
                        $products = $this->db->get_where('product', array('sub_category' => $row1['sub_category_id'], 'status' => 'ok'))->result_array();
                        ?>
                        <div class="col-md-12"><h3 class="text-center" style="background:#EAEAEA;"><?php echo $row1['sub_category_name']; ?></h3></div>
                        <?php
                        foreach ($products as $row2) {
                            if ($this->crud_model->is_publishable($row2['product_id'])) {
                                ?>
                                <div class="col-md-3">
                                    <div class="menu_box">
                                        <div class="img_menu_box" style="background:url('<?php echo $this->crud_model->file_view('product', $row2['product_id'], '', '', 'no', 'src', 'multi', 'one') ?>') no-repeat center center; background-size: 100% auto;">
                                        </div>

                                        <a href="<?php echo $this->crud_model->product_link($row2['product_id']); ?>">
                                            <?php echo $row2['title']; ?>
                                        </a>

                                    </div>
                                </div>
                                <?php
                            }
                        }
                        ?>
                        <?php
                    }
                    ?>
                </div>
            </div>
        </li>

        <?php
    }
    ?>


</ul>

这是我得到的结果

print_r($categories);
结果 = 数组 ( [0] => 5 [1] => 31 )
print_r($subs);
1- Array [0] => 5 = ( [0] => Array ( [sub_category_id] => 18 [sub_category_name] => A [category] ​​=> 5 ) [1] 结果 => 数组 ( [sub_category_id] => 19 [sub_category_name] => B [category] ​​=> 5 ))
数组 [1] 的 2- 结果 => 31 = 数组 ( )

问题在于第二个数组结果为空

 1-   **category table & data**
        category_id | category_name
            5              cat1
           31              cat2

2-   **Sub category table & data**
    sub_category_id | sub_category_name | category
          1              C                 31
          2              D                 31
          18             A                  5
          19             B                  5
3- ui_settings table & data
ui_settings_id  |     type      |         value
       10         home_category    ["5","31"]

预期结果
数组 [1] => 31 = ( [0] => 数组 ( [sub_category_id] => 1 [sub_category_name] => C [category] ​​=> 31 ) [1] => 数组 ([sub_category_id] => 2[sub_category_name] => D [category] ​​=> 31))

Answer 1

先查表 ->sub_category 是否有 category = 31 的记录