CodeIgniter中多选下拉框已选值回显：编辑页面的实现指南

<?php
defined('BASEPATH') OR exit('No direct script access allowed');

class Client_model extends CI_Model {

    // 获取所有可用的系统用户 (管理员)
    public function get_all_system_users() {
        return $this->db->get('system_usertable')->result_array();
    }

    // 获取特定用户已分配的管理员ID列表
    public function get_assigned_admin_ids($user_id) {
        $this->db->select('admin_id');
        $this->db->where('user_id', $user_id);
        $query = $this->db->get('assignuserstable');
        $assigned_ids = [];
        foreach ($query->result_array() as $row) {
            $assigned_ids[] = $row['admin_id']; // 将所有admin_id收集到一个数组中
        }
        return $assigned_ids; // 返回例如 [1, 5, 7] 这样的数组
    }

    // ... 其他方法，例如保存数据等
    public function addclientdetails() {
        // ... 其他数据插入 ...

        $data['SU_id'] = html_escape($this->input->post('admin_id')); // 这个可能用于单选，或主表关联
        $this->db->insert('user_table', $data);
        $insertId = $this->db->insert_id();

        // 处理多选管理员的批量插入
        $admin_idd = $this->input->post('admin_idd'); // 这是一个数组
        if (!empty($admin_idd)) {
            $result = array();
            foreach ($admin_idd as $admin_id_val) {
                 $result[] = array(
                  'user_id'   => $insertId,
                  'admin_id'  => html_escape($admin_id_val), // 确保值被清理
                  'user_type' => html_escape($this->input->post('user_type')), // 如果需要
                 );
            }
            $this->db->insert_batch('assignuserstable', $result);
        }
        return $insertId;
    }
}

<?php
defined('BASEPATH') OR exit('No direct script access allowed');

class Client extends CI_Controller {

    public function __construct() {
        parent::__construct();
        $this->load->model('client_model'); // 加载模型
        // ... 其他加载项和身份验证
    }

    public function edit($user_id) {
        // 获取所有可用的系统用户
        $data['all_system_users'] = $this->client_model->get_all_system_users();

        // 获取当前用户已分配的管理员ID列表
        $data['assigned_admin_ids'] = $this->client_model->get_assigned_admin_ids($user_id);

        // 加载视图并传递数据
        $this->load->view('your_header'); // 假设有头部文件
        $this->load->view('client/edit_client', $data);
        $this->load->view('your_footer'); // 假设有底部文件
    }

    // ... 其他方法，例如处理表单提交
    public function update_client_details() {
        if ($this->client_model->addclientdetails()) { // 调用模型方法处理数据
            $this->session->set_flashdata('flash_message', 'Client updated successfully.');
            redirect(base_url('client/list'));
        } else {
            $this->session->set_flashdata('error_message', 'Failed to update client.');
            redirect(base_url('client/edit/' . $this->input->post('user_id')));
        }
    }
}

<!-- application/views/client/edit_client.php -->

<div class="form-group col-md-6">
    <label for="admin_id"><?php echo get_phrase('Assign User'); ?>
        <span class="text-danger">*</span></label>
    <select class="form-control selectpicker" name="admin_idd[]" id="admin_id"
        placeholder="Assign User" required multiple>

        <option value="" hidden><?php echo get_phrase('Select User'); ?></option>
        <?php
        // 遍历所有可用的系统用户
        foreach($all_system_users as $row2):
            // 检查当前用户的admin_id是否在已分配的admin_id数组中
            $selected = (in_array($row2['admin_id'], $assigned_admin_ids)) ? 'selected' : '';
        ?>
            <option value="<?php echo $row2['admin_id'];?>" <?php echo $selected; ?>>
                <?php echo $row2['first_name'];?>
            </option>
        <?php
        endforeach;
        ?>
    </select>
</div>

<!-- 确保引入了 jQuery 和 Bootstrap Select (selectpicker) 的JS/CSS文件 -->
<!-- 例如： -->
<!-- <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script> -->
<!-- <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/bootstrap-select/1.13.18/css/bootstrap-select.min.css"> -->
<!-- <script src="https://cdnjs.cloudflare.com/ajax/libs/bootstrap-select/1.13.18/js/bootstrap-select.min.js"></script> -->
<script>
    $(document).ready(function() {
        $('.selectpicker').selectpicker(); // 初始化 selectpicker
    });
</script>