所以我对多对多的关系有问题。目前，我有 surat 以及 surat_user table。如何将数据插入到 surat 同时从中插入多个值 select2 多种形式 surat_user 表以及如何获取数据以便我可以更新它。
更新：我解决了插入问题，请看下面的答案
但现在我不知道如何更新这些值。例如 surat_user ```
id_surat | id_user
1 | 1
1 | 2

如何更新 `surat_user` （在控制器和模型中）如果要删除 `id_user` 其中“id\u surat=1”
目前，我不知道如何将多个值提取到select2 form edit中，因此下面是mu uncomplete代码：
控制器

public function edit_sm($id_surat){
$this->load->view('template/header');
$this->load->view('template/sidebar');
$where = array('id_surat' => $id_surat);
//$data=array('id_status'=> $this->M_sm->get_option());
$data['surat'] = $this->M_sm->edit_sm($where,'surat')->result();
$this->load->view('v_edit_surat',$data);
$this->load->view('template/footer');
}

public function edit_sm_proses() {
$data = array(
'id_surat'=>$this->input->post('id_surat'),
'no_surat'=>$this->input->post('no_surat'),
'id_status'=>$this->input->post('id_status'),
'id_user'=>$this->input->post('id_user')
);
$where = array(
'id_surat' => $id_surat
);

$this->M_sm->edit_sm_proses($where,$data,'surat');
redirect('SuratMasuk');

}

型号：

public function edit_sm($where,$table){
$this->db->join('status_surat', 'status_surat.id_status = surat.id_status');
return $this->db->get_where($table,$where);
}

public function edit_sm_proses($where,$data,$table){
$this->db->where($where);
$this->db->update($table,$data);
}

看法

    <div class="form-group">
      <label class="control-label col-lg-2">No Surat</label>
      <div class="col-lg-5">
        <input type="text" name="no_surat" class="form-control no_surat" placeholder="Masukkan Nomor Surat" value="<?=$key->no_surat?>">
        <span class="help-block"></span>
      </div>
    </div>
    <br>
    <br>
    <div class="form-body">
    <div class="form-group">
      <label class="control-label col-lg-2">Status</label>
      <div class="col-lg-5">
        <select class="form-control select2 id_status" name="id_status" style="width: 100%;">
            <option value="<?=$key->id_status;?>" selected="<?=$key->id_status;?>"><?php echo $key->status;?></option>
            <?php foreach ($id_status as $row) { ?>
            <option value="<?php echo $row->id_status; ?>"> <?php echo $row->status; ?></option>

            <?php } ?>
            </select>
       <span class="help-block"></span>
      </div>
    </div>
  </div>
  <br>
  <br>
  <div class="form-body">
    <div class="form-group">
      <label class="control-label col-lg-2">Disposisi</label>
      <div class="col-lg-5">
        <select class="form-control select2 id_user" name="id_user[]" style="width: 100%;">
            <option value="<?=$key->id_user;?>" selected="<?=$key->id_user;?>"><?php echo $key->nama;?></option>
            <?php foreach ($id_user as $row) { ?>
            <option value="<?php echo $row->id_user; ?>"> <?php echo $row->nama; ?></option>

            <?php } ?>
            </select>
       <span class="help-block"></span>
      </div>
    </div>
  </div>  
      </div>
      <!-- /.box-body -->
      <div class="box-footer">
       <button class="btn btn-danger" type="reset" value="reset">Reset</button>
       <button class="btn btn-info">Update</button><br>
       <a href="<?php echo base_url(); ?>SuratMasuk/">Kembali</a>
      </form>
       <?php  
            }
            ?>
      </div>
      <!-- box-footer -->
      </div>
      <!-- /.box -->
</div>
<!-- /.col -->