Codeigniter获取行

Question

我在我的网站上使用codeigniter，但是我有一个问题我已经完成了从不同表中返回行的脚本。但它写了我错误试图获取非对象的属性。这是我的代码。哪里有问题？

      $this->db->select('*');
      $this->db->from('orders');
      $this->db->where('order_id',$order_id);
      $array_keys_values = $this->db->get();
      $row = $array_keys_values->row();

      $this->db->select('*');
      $this->db->from('pacients');
      $this->db->where('pacient_account_id',$row->order_pacient_id);
      $array_keys_values2 = $this->db->get();
      $row2 = $array_keys_values2->row();

      $this->db->select('*');
      $this->db->from('doctors');
      $this->db->where('doctor_account_id',$doctor_id);
      $array_keys_values3 = $this->db->get();
      $row3 = $array_keys_values3->row();

Answer 1

尝试

$this->db->select('*');
$this->db->from('orders');
$this->db->where('order_id',$order_id);
$array_keys_values = $this->db->get();    
if ($array_keys_values->num_rows() > 0) {
    foreach ($array_keys_values->result() as $row) {
       // now you can work with $row
    }
}

$this->db->select('*');
$this->db->from('pacients');
$this->db->where('pacient_account_id',$row->order_pacient_id);
$array_keys_values2 = $this->db->get();
if ($array_keys_values2->num_rows() > 0) {
    foreach ($array_keys_values2->result() as $row2) {
        // now you can work with $row2
    }
}

$this->db->select('*');
$this->db->from('doctors');
$this->db->where('doctor_account_id',$doctor_id);
$array_keys_values3 = $this->db->get();
if ($array_keys_values3->num_rows() > 0) {
    foreach ($array_keys_values3->result() as $row3) {
        // now you can work with $row3
    }
}

Answer 2

没有返回任何行。使用带有num_rows（）＆gt;的if语句0来检查