使用mysql或php对带有tags的tag进行分组/格式化

可以说我们有一个像这样的数组

从像

function getGroups($limit = 10) {
    $data = $this->fetchAll ( 'SELECT gid, `group`, information, tag FROM groups 
    GROUP BY tag LIMIT ' . $limit );
    return $data;
}

结果

array
  0 => 
    array
      'gid' => string '6' (length=1)
      'group' => string 'Media' (length=5)
      'tag' => string 'advertising' (length=11)
  1 => 
    array
      'gid' => string '8' (length=1)
      'group' => string 'Fashion' (length=10)
      'tag' => string 'shorts' (length=7)
  2 => 
    array
      'gid' => string '7' (length=1)
      'group' => string 'Automotive' (length=8)
      'tag' => string 'cars' (length=5)
  3 => 
    array
      'gid' => string '1' (length=1)
      'group' => string 'Fashion' (length=7)
      'tag' => string 'tshirt' (length=6)

我需要对此显示某种方式(类似)

array
   0 =>
     array
       'group' => string 'Media'
       'tags' 
          array 
          0 => string 'advertising'

   1 =>
     array
       'group' => string 'Fashion'
       'tags'
          array 
          0 => string 'short'
          1 => string 'tshirt'   
   2 =>
     array
       'group' => string 'Automotive'
       'tags'
          array
          0 => 'cars'  

更简单

group      tag
media      advertising
fashion    short
fashion    tshirt
automotive cars

至

media
  advertising
fashion
  short
  tshirt
automotive
  cars

做这个的最好方式是什么？从PHP数组？还是从MySQL？

解决方法:

您是否要获取组列表以及每个组的所有标签？ GROUP_CONCAT()是获取标签列表的正确方法,但是您希望按组而不是按标签分组：

function getGroups($limit = 10) {
    $data = (array) $this->fetchAll (
        'SELECT `group`,
        GROUP_CONCAT(DISTINCT `tag` ORDER BY `tag`) AS `tags`
        FROM `groups`
        GROUP BY `group` LIMIT ' . $limit
    );
    foreach ($data as $i => $row) {
        $data[$i]['tags'] = explode(',', $row['tags']);
    }
    return $data;
}

标签：arrays,mysql,php,formatting
来源： https://codeday.me/bug/20191208/2090662.html