由于在Codeigniter 4中接收到血型外键，我很难在患者表中显示血型描述。
错误发生在<td><?php echo $p['bt']['description']; ?></td>显示ErrorException Undefined array key "bt"

• PacientModel.php个

class PacientModel extends Model
{
    ...
    public function bt()
    {
        return $this->belongsTo(BloodTypeModel::class, 'blood_type_id');
    }
}

字符串

• BloodTypeModel.php个

class BloodTypeModel extends Model
{
    ...
    public function blood_type()
    {
        return $this->hasMany(PacientModel::class, 'blood_type_id');
    }
}

型

• PacientController.php个

public function index()
    {
        $model = new PacientModel();
        $blood_type = new BloodTypeModel();

        $blood_types = $blood_type->findAll();
        $blood_types = array_column($blood_types, null, 'id');

        $pacients = [
            'pacients' => $model->paginate(10),
            'pager' => $model->pager,
            'blood_types' => $blood_types, 
        ];
        return view('pacient/index', $pacients);
    }

型

• index.php个

<?php foreach($pacients as $p): ?>
   <tr> 
     <td><?php echo $p['bt']['description']; ?> </td>
   </tr>
  <?php endforeach; ?>

型