Php Codeigniter：当使用选择选项（Form_下拉菜单）编辑我的数据时，表单变得很奇怪

当我使用CI上的选择选项输入数据时，它工作正常，但当我再次尝试编辑或更新数据时，我的表单变得像这样奇怪（请参见图片编辑表单）

这里是我的控制器：

型号

public function update_obat($kode_obat){
        $nama_obat = $this->input->post('nama_obat');
        $kode_jenis_obat = $this->input->post('kode_jenis_obat');
        $stok= $this->input->post('stok');
        $data = array('nama_obat' => $nama_obat,
                        'kode_jenis_obat' => $kode_jenis_obat,
                        'stok' => $stok,

                        );
        $this->db->where('kode_obat',$kode_obat);
        $this->db->update('tb_obat',$data);
    }

public function select2($kode_obat){
    return $this->db->get_where('tb_obat', array('kode_obat' => $kode_obat))->row();
}

 <!-- Main content -->

<section class="content">
<div class="row">
    <!-- left column -->
    <div class="col-md-8">
      <!-- general form elements -->
        <div class="box box-primary">
        <div class="box-header with-border">
          <h3 class="box-title">Silahkan melakukan edit stok obat</h3>
        </div>
        <!-- /.box-header -->
        <!-- form start -->
        <form role="form" action="<?php echo base_url().'index.php/a_controller/updateobat/'.$hasil->kode_obat; ?>" method="post">
          <div class="box-body">

            <div class="form-group">
              <label for="exampleInputNama">Nama Obat</label>
                <div class="input-group">
                <span class="input-group-addon"><i class="fa fa-medkit"></i></span>
                <input type="text" class="form-control" name="nama_obat" id="exampleInputNama" placeholder="Nama Obat" action="<?php echo form_input('nama_obat',$hasil->nama_obat);?>">
              </div>
            </div>

            <div class="form-group">
                <label for="exampleInputJenis">Jenis Obat</label>
                <div class="input-group">
                <span class="input-group-addon"><i class="fa fa-list"></i></span>


                  <select name="kode_jenis_obat" class="form-control" action="<?php echo form_dropdown('kode_jenis_obat',$hasil->kode_jenis_obat);?>">
                    <option value="none" selected="selected">Pilih Jenis Obat</option>
                    <!-----Displaying fetched cities in options using foreach loop ---->
                    <?php foreach($tb_jenisobat as $jenisobat):?>
                    <option value="<?php echo $jenisobat->kode_jenis_obat?>"><?php echo $jenisobat->nama_jenis_obat?></option>
                    <?php endforeach;?>

                  </select>

              </div>
            </div>

            <div class="form-group">
              <label for="exampleInputUsername">Stok Obat</label>
                <div class="input-group">
                <span class="input-group-addon"><i class="fa fa-list"></i></span>
                <input type="text" class="form-control" name="stok" id="exampleInputUsername" placeholder="Stok" action="<?php echo form_input('stok',$hasil->stok);?>">
              </div>
            </div>

          </div>
          <!-- /.box-body -->

          <div class="box-footer">
            <button type="submit" class="btn btn-primary">Submit</button>
          </div>
        </form>
      </div>
      <!-- /.box -->
    </div>
</div>
  <!-- /.row -->
</section>

查看

public function update_obat($kode_obat){
        $nama_obat = $this->input->post('nama_obat');
        $kode_jenis_obat = $this->input->post('kode_jenis_obat');
        $stok= $this->input->post('stok');
        $data = array('nama_obat' => $nama_obat,
                        'kode_jenis_obat' => $kode_jenis_obat,
                        'stok' => $stok,

                        );
        $this->db->where('kode_obat',$kode_obat);
        $this->db->update('tb_obat',$data);
    }

public function select2($kode_obat){
    return $this->db->get_where('tb_obat', array('kode_obat' => $kode_obat))->row();
}

 <!-- Main content -->

<section class="content">
<div class="row">
    <!-- left column -->
    <div class="col-md-8">
      <!-- general form elements -->
        <div class="box box-primary">
        <div class="box-header with-border">
          <h3 class="box-title">Silahkan melakukan edit stok obat</h3>
        </div>
        <!-- /.box-header -->
        <!-- form start -->
        <form role="form" action="<?php echo base_url().'index.php/a_controller/updateobat/'.$hasil->kode_obat; ?>" method="post">
          <div class="box-body">

            <div class="form-group">
              <label for="exampleInputNama">Nama Obat</label>
                <div class="input-group">
                <span class="input-group-addon"><i class="fa fa-medkit"></i></span>
                <input type="text" class="form-control" name="nama_obat" id="exampleInputNama" placeholder="Nama Obat" action="<?php echo form_input('nama_obat',$hasil->nama_obat);?>">
              </div>
            </div>

            <div class="form-group">
                <label for="exampleInputJenis">Jenis Obat</label>
                <div class="input-group">
                <span class="input-group-addon"><i class="fa fa-list"></i></span>


                  <select name="kode_jenis_obat" class="form-control" action="<?php echo form_dropdown('kode_jenis_obat',$hasil->kode_jenis_obat);?>">
                    <option value="none" selected="selected">Pilih Jenis Obat</option>
                    <!-----Displaying fetched cities in options using foreach loop ---->
                    <?php foreach($tb_jenisobat as $jenisobat):?>
                    <option value="<?php echo $jenisobat->kode_jenis_obat?>"><?php echo $jenisobat->nama_jenis_obat?></option>
                    <?php endforeach;?>

                  </select>

              </div>
            </div>

            <div class="form-group">
              <label for="exampleInputUsername">Stok Obat</label>
                <div class="input-group">
                <span class="input-group-addon"><i class="fa fa-list"></i></span>
                <input type="text" class="form-control" name="stok" id="exampleInputUsername" placeholder="Stok" action="<?php echo form_input('stok',$hasil->stok);?>">
              </div>
            </div>

          </div>
          <!-- /.box-body -->

          <div class="box-footer">
            <button type="submit" class="btn btn-primary">Submit</button>
          </div>
        </form>
      </div>
      <!-- /.box -->
    </div>
</div>
  <!-- /.row -->
</section>

我可以编辑stok obat