我有一个数据表，我需要搜索结果显示的列名
我有这张table

id address        city      zipcode  state  country
1  12, street     arizona   1234     abcd   new island
2  abcd,stree     abcd      7895     abcd   us
3  new av         mumbai    6875     abcd   uk
4  abcd, street   test ci   5687     abcd   new island
5  6741, street   df df     12345    abcd   uae

我需要什么，如果有人搜索让说“d”我希望结果显示如下
5个与“d”匹配的地址
城市、邮政编码、州和国家各1个
所以基本上我想在一个查询中限制地址以获得5个地址，限制1个城市（如果可用），限制1个zipcode（如果可用），限制1个州（如果可用），限制1个国家（如果可用）。
关键字还应该查找每一列，而不仅仅是地址。我通过使用多个查询实现了这一点

$query = $this->db->query("SELECT city FROM ".$this->db->dbprefix('prison')." WHERE city like'%".$keyword."%' LIMIT 1");
    $query2 = $this->db->query("SELECT zipcode FROM ".$this->db->dbprefix('prison')." WHERE zipcode like'%".$keyword."%' LIMIT 1");
    $query3 = $this->db->query("SELECT state FROM ".$this->db->dbprefix('prison')." WHERE state like'%".$keyword."%' LIMIT 1");
    $query4 = $this->db->query("SELECT address FROM ".$this->db->dbprefix('prison')." WHERE address like'%".$keyword."%' LIMIT 10");
    $query5 = $this->db->query("SELECT country FROM ".$this->db->dbprefix('prison')." WHERE country like'%".$keyword."%' LIMIT 1");

    $result_array = [];
    $result_array['cities'] =  $query->row();
    $result_array['zipcode'] =  $query2->row();
    $result_array['state'] =  $query3->row();
    $result_array['address'] =  $query4->result();
    $result_array['country'] =  $query5->row();

    return $result_array;

我是否可以在一个查询中实现这一点？这个解决方案是否可行？我在keyup上通过ajax显示结果，所以我担心运行多个查询会影响结果的加载时间。
我还尝试了一个使用联合运算符的解决方案，它确实提供了我需要的结果，但没有提供标识符来查看它是城市、州还是zipcode

$query = $this->db->query("SELECT prison_city FROM ".$this->db->dbprefix('prison')." WHERE prison_city like'%".$keyword."%' LIMIT 1 UNION SELECT prison_zipcode FROM ".$this->db->dbprefix('prison')." WHERE prison_zipcode like'%".$keyword."%' LIMIT 1 UNION SELECT prison_state FROM ".$this->db->dbprefix('prison')." WHERE prison_state like'%".$keyword."%' LIMIT 1 UNION SELECT prison_country FROM ".$this->db->dbprefix('prison')." WHERE prison_country like'%".$keyword."%' LIMIT 1 UNION SELECT prison_address FROM ".$this->db->dbprefix('prison')." WHERE prison_address like'%".$keyword."%' LIMIT 10");

    return $query->result();

它输出这些数据

Array ( 
  [0] => stdClass Object ( [prison_city] => Susanville ) 
  [1] => stdClass Object ( [prison_city] => California ) 
  [2] => stdClass Object ( [prison_city] => 24900 CA-202 ) 
  [3] => stdClass Object ( [prison_city] => New York, America ) 
  [4] => stdClass Object ( [prison_city] => 1 Kings Way, Avenal, CA 93204, USA ) 
  [5] => stdClass Object ( [prison_city] => 14901 Central Ave ) 
  [6] => stdClass Object ( [prison_city] => 19025 Wiley's Well Road ) 
  [7] => stdClass Object ( [prison_city] => 23500 Kasson Rd ) 
  [8] => stdClass Object ( [prison_city] => 475-750 Rice Canyon Rd ) 
  [9] => stdClass Object ( [prison_city] => 19005 Wiley's Well Road ) 
)

它有两个问题，首先它没有给出标识符，第二个是我为它应用于整个结果的地址设置的限制。