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使用 SQL 和 PHP 从不同的引用表中获取分层树

Get a hierarchical tree from different referenced tables with SQL and PHP

本文关键字：引用 获取 分层 SQL PHP 使用 | 更新日期: 2023-09-27

我有多个表，它们都具有相似的基本结构：

biopsy_p0
id | biopsy_id    | introduced
biopsy_p1
id | biopsy_p0_id | introduced
biopsy_p2
id | biopsy_p1_id | introduced

我的目标是获得依赖项的树视图

biopsy_p0.id->biopsy_p1.biopsy_p0_id->biopsy_p2.biopsy_p1_id

我

尝试只用SQL来做，但正如你从我的问题中看到的那样，我在这方面不是很有经验。到目前为止，我能找到的所有内容都是关于分层树的参考资料。但是那些总是只使用一个带有内部引用的表。

---更新：我现在让它与 PHP 一起工作，这真的不是一个很好的解决方案，我希望我可以用 SQL 来制作它，这样扩展起来会更好一些：

PHP代码：

  $database = DatabaseFactory::getFactory()->getConnection();
      // Get all p0 element asociated with the biopsy
      $sql = "SELECT *
              FROM biopsy_p0
              WHERE biopsy_id = :id";
      $query = $database->prepare($sql);
      $query->execute(array(':id' => $id));
      $p0 = $query->fetchAll();
      // Get all p1 elements
      $sql="SELECT *
            FROM biopsy_p0 as p0
            RIGHT JOIN biopsy_p1 as p1
            ON p0.id=p1.biopsy_p0_id
            WHERE biopsy_id = :id;";
      $query = $database->prepare($sql);
      $query->execute(array(':id' => $id));
      $p1 = $query->fetchAll();
      for ($i=0; $i < count($p0); $i++)
      {
        $p1Array = new ArrayObject();
        foreach ($p1 as $key => $value)
        {
          if ($value->biopsy_p0_id == $p0[$i]->id)
          {
             $p1Array->append($value);
          }
          $p0[$i]->p1 = $p1Array;
        }
        unset($p1Array);
      }
      if ($p0 != NULL){
        return $p0;
      }
      return FALSE;

结果：这正是我所需要的，但是PHP很混乱，并且随着我想检查的每个子级别而增加复杂性。

 details:   Array
(
    [0] => stdClass Object
        (
            [id] => 1
            [biopsy_id] => 226
            [introduced] => 2014-12-31
            [p1] => ArrayObject Object
                (
                    [storage:ArrayObject:private] => Array
                        (
                            [0] => stdClass Object
                                (
                                    [id] => 1
                                    [biopsy_id] => 226
                                    [introduced] => 2015-03-18
                                    [biopsy_p0_id] => 1
                                )
                            [1] => stdClass Object
                                (
                                    [id] => 3
                                    [biopsy_id] => 226
                                    [introduced] => 2015-03-17
                                    [biopsy_p0_id] => 1
                                )
                            [2] => stdClass Object
                                (
                                    [id] => 4
                                    [biopsy_id] => 226
                                    [introduced] => 2015-03-18
                                    [biopsy_p0_id] => 1
                                )
                        )
                )
        )
    [1] => stdClass Object
        (
            [id] => 2
            [biopsy_id] => 226
            [introduced] => 2014-12-31
            [p1] => ArrayObject Object
                (
                    [storage:ArrayObject:private] => Array
                        (
                            [0] => stdClass Object
                                (
                                    [id] => 2
                                    [biopsy_id] => 226
                                    [introduced] => 2015-03-31
                                    [biopsy_p0_id] => 2
                                )
                            [1] => stdClass Object
                                (
                                    [id] => 6
                                    [biopsy_id] => 226
                                    [introduced] => 2015-03-01
                                    [biopsy_p0_id] => 2
                                )
                        )
                )
        )
    [2] => stdClass Object
        (
            [id] => 3
            [biopsy_id] => 226
            [introduced] => 2014-12-31
            [p1] => ArrayObject Object
                (
                    [storage:ArrayObject:private] => Array
                        (
                            [0] => stdClass Object
                                (
                                    [id] => 5
                                    [biopsy_id] => 226
                                    [introduced] => 2015-03-11
                                    [biopsy_p0_id] => 3
                                )
                        )
                )
        )
)

SQL 数据：

CREATE TABLE IF NOT EXISTS `biopsy` (
  `id` int(11) unsigned NOT NULL,
  `creation_date` date NOT NULL
) ENGINE=InnoDB AUTO_INCREMENT=228 DEFAULT CHARSET=latin1;
INSERT INTO `biopsy` (`id`, `creation_date`) VALUES
(226, '2015-03-08'),
(227, '2015-03-08');
CREATE TABLE IF NOT EXISTS `biopsy_p0` (
`id` int(11) unsigned NOT NULL,
  `biopsy_id` int(11) unsigned NOT NULL,
  `introduced` date NOT NULL
) ENGINE=InnoDB AUTO_INCREMENT=7 DEFAULT CHARSET=latin1;
INSERT INTO `biopsy_p0` (`id`, `biopsy_id`, `introduced`) VALUES
(1, 226, '2014-12-31'),
(2, 226, '2014-12-31'),
(3, 226, '2014-12-31'),
(4, 227, '2015-03-14'),
(5, 255, '2015-03-10'),
(6, 255, '2015-03-12');
CREATE TABLE IF NOT EXISTS `biopsy_p1` (
`id` int(11) unsigned NOT NULL,
  `biopsy_p0_id` int(11) unsigned NOT NULL,
  `introduced` date NOT NULL
) ENGINE=InnoDB AUTO_INCREMENT=7 DEFAULT CHARSET=latin1;
INSERT INTO `biopsy_p1` (`id`, `biopsy_p0_id`, `introduced`) VALUES
(1, 1, '2015-03-18'),
(2, 2, '2015-03-31'),
(3, 1, '2015-03-17'),
(4, 1, '2015-03-18'),
(5, 3, '2015-03-11'),
(6, 2, '2015-03-01');

也许最好有一个通过 ID 引用另一个存储实际数据的表的分层关系表......所以我只涉及两个表，如果添加新元素会更灵活......

让我们从声明键开始：

CREATE TABLE IF NOT EXISTS `biopsy` (
  `id` int(11) unsigned NOT NULL primary key,
  `creation_date` date NOT NULL
) ENGINE=InnoDB AUTO_INCREMENT=228 DEFAULT CHARSET=latin1;
INSERT INTO `biopsy` (`id`, `creation_date`) VALUES
(226, '2015-03-08'),
(227, '2015-03-08');
CREATE TABLE IF NOT EXISTS `biopsy_p0` (
`id` int(11) unsigned NOT NULL primary key,
`biopsy_id` int(11) unsigned NOT NULL,
`introduced` date NOT NULL
) ENGINE=InnoDB AUTO_INCREMENT=7 DEFAULT CHARSET=latin1;
alter table biopsy_p0 add constraint fk_biopsy
    foreign key (biopsy_id)
    references biopsy (id)
        on update cascade
        on delete cascade;
INSERT INTO `biopsy_p0` (`id`, `biopsy_id`, `introduced`) VALUES
(1, 226, '2014-12-31'),
(2, 226, '2014-12-31'),
(3, 226, '2014-12-31'),
(4, 227, '2015-03-14');
-- violates the f.k. introduced
-- (5, 255, '2015-03-10'),
-- (6, 255, '2015-03-12');
CREATE TABLE IF NOT EXISTS `biopsy_p1` (
  `id` int(11) unsigned NOT NULL primary key,
  `biopsy_p0_id` int(11) unsigned NOT NULL,
  `introduced` date NOT NULL
) ENGINE=InnoDB AUTO_INCREMENT=7 DEFAULT CHARSET=latin1;
alter table biopsy_p1 add constraint fk_biopsy_p0
    foreign key (biopsy_p0_id)
    references biopsy_p0 (id)
        on update cascade
        on delete cascade;
INSERT INTO `biopsy_p1` (`id`, `biopsy_p0_id`, `introduced`)     
VALUES
(1, 1, '2015-03-18'),
(2, 2, '2015-03-31'),
(3, 1, '2015-03-17'),
(4, 1, '2015-03-18'),
(5, 3, '2015-03-11'),
(6, 2, '2015-03-01');

我建议您为事物命名，即不要命名 id 列 id 并在模型中的其他地方更改名称。例：

CREATE TABLE IF NOT EXISTS biopsy (
  biopsy_id int unsigned NOT NULL primary key,
  creation_date date NOT NULL
) ENGINE=InnoDB AUTO_INCREMENT=228 DEFAULT CHARSET=latin1;

但我会把它放在一边。现在我们知道数据是一致的：

select x.id as biopsy_id, x.creation_date
     , y.id as biopsy_p0_id, y.introduced as biopsy_p0_introduction
     , z.id as biopsy_p1_id, z.introduced as biopsy_p1_introduction 
from biopsy as x 
left join biopsy_p0 as y 
    on y.biopsy_id = x.id 
left join biopsy_p1 as z 
    on z.biopsy_p0_id = y.id 
order by x.id, y.id, z.id;
+-----------+---------------+--------------+------------------------+--------------+------------------------+
| biopsy_id | creation_date | biopsy_p0_id | biopsy_p0_introduction | biopsy_p1_id | biopsy_p1_introduction |
+-----------+---------------+--------------+------------------------+--------------+------------------------+
|       226 | 2015-03-08    |            1 | 2014-12-31             |            1 | 2015-03-18             |
|       226 | 2015-03-08    |            1 | 2014-12-31             |            3 | 2015-03-17             |
|       226 | 2015-03-08    |            1 | 2014-12-31             |            4 | 2015-03-18             |
|       226 | 2015-03-08    |            2 | 2014-12-31             |            2 | 2015-03-31             |
|       226 | 2015-03-08    |            2 | 2014-12-31             |            6 | 2015-03-01             |
|       226 | 2015-03-08    |            3 | 2014-12-31             |            5 | 2015-03-11             |
|       227 | 2015-03-08    |            4 | 2015-03-14             |         NULL | NULL                   |
+-----------+---------------+--------------+------------------------+--------------+------------------------+
7 rows in set (0.00 sec)

剩下的就是纯粹的呈现，最好在 php 中完成。

对于您的一般问题，是否最好将结构信息保存在一个表中，我会说，如果您有少量固定水平，您的解决方案很好。

对于大量的级别，或者如果数量未知，你需要某种递归结构（请注意，你还需要提出这类问题的方法，现在大多数DBMS：s都有递归公共表表达式，但MySQL没有。你可以用变量解决某些事情，但它很快就会变得混乱）。Troels Arvin在以下位置有一系列链接：

http://troels.arvin.dk/db/rdbms/links/#hierarchical

您可能会觉得有用。

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