php - Mysql 加入 1 行与多行 - 组 concat 或 php？

Question

考虑以下示例:

+----------+--------+-------------+----------+
| Person_id| Person | Language_id | Language |
+----------+--------+-------------+----------+
| 1        | Bob    | 5           | English  |
| 1        | Bob    | 3           | Italiano |
| 1        | Bob    | 8           | Deutsch  |
+----------+--------+-------------+----------+

查询是(不是那么重要，只是编写脚本来向您展示表结构):

SELECT pl.Person_id, Person, Language_id, Language FROM people as p
LEFT JOIN people_languages as pl ON p.Person_id = pl.Person_id 
LEFT JOIN languages as l ON pl.language_id = l.language_id
WHERE pl.Person = 1;

所以基本上，如果表是以这种方式构建的，是检索如上所示的所有结果然后创建一个 php 函数来创建一个 person Model with languages_id 和 languages 在一个数组中，还是使用 group_concat 更好？ 来检索一行，然后将语言和 languages_id 分解成一个数组？

顺便说一句，无论我做什么，最后我都希望有一个如下的人物模型:

class Person { 

    public $person_id; // 1
    public $person; // Bob
    public $language_id; // Array(5, 3, 8)
    public $language; // Array(English, Italiano, Deutsch);

    .
    . // Functions 
    .

}

Answer 1

我认为你应该将查询分离到它们单独的模型中

应该有一个Language 模型并且会保持简单

class Language
{
   function getId() { return $id; }
   function getDescription { return $description; }
}


class Person { 

public $person_id; // 1
public $person; // Bob
public $languages; //this will store array of Language object

}

//来自数据访问

function getPerson($person_id)
{
    $person = new Person();
    //select only from Person table
    //fill $person properties from records
    //$person.person_id = $row['person_id']; etc

    //select from people_languages joined to language where person_id=$person_id
    $person->languages = getLanguagesByPerson($person->person_id); //returns array of languages

    return $person;
}

你现在可以拥有

$person = getPerson(123);
$person->langauges[0]->getId(); //language id
$person->langauges[0]->getDescription(); //language id

$person->langauges[1]->getId(); //language id
$person->langauges[1]->getDescription(); //language id

或者遍历语言

foreach($person->languages as $lang)
{
   //use($lang->getId());
   //use($lang->getDescription();
}