SQL結合を使用して投稿タグを取得する

Question

1つのSQLクエリで各ブログ投稿のタグを取得しようとしています。私はpostsテーブル、post_tagsテーブル、tagsテーブルを持っています。投稿とタグの多対多関係を削除するには、post_tagsテーブルが存在します。

| p_id | c_id | u_id | title |  body |  published  | 
---------------------------------------------------------------------- 
| 1 | 1 | 1 | first post| lorem ipsum | 2012-01-27 18:37:47 | 


| p_id | t_id | 
--------------- 
| 1 | 3 | 


| t_id |  name |  slug | 
------------------------------------ 
| 3 | programming | programming | 

そして、私が使用しているPHP方法：ここでは、それらのテーブルのスキーマのITはちょっと作品

public function getLatestPosts() 
{ 
    $query = $this->db->query('SELECT title, clean_title, body, published, name, slug 
           FROM posts 
           LEFT JOIN post_tags ON posts.p_id=post_tags.p_id 
           LEFT JOIN tags ON post_tags.t_id=tags.t_id 
           ORDER BY published DESC'); 
    $posts = array(); 
    foreach ($query->result() as $row) 
    { 
     $posts[] = array('title' => $row->title, 
          'clean_title' => $row->clean_title, 
          'body' => $row->body, 
          'published' => $row->published, 
          'tags' => array('name' => $row->name, 
              'slug' => $row->slug)); 
    } 
    print_r($posts); 
    return $posts; 
} 

、ポストのタグは、各ポストのために検索されているが、私は重複した投稿があり。ここでは、クエリの結果のprint_rダンプです：

Array 
(
    [0] => Array 
     (
      [title] => Second blog post, this is a pretty long title 
      [clean_title] => second-blog-post-this-is-a-pretty-long-title 
      [body] => Lorem ipsum dolor sit amet, consectetur adipiscing elit. Phasellus eget est sit amet libero volutpat eleifend facilisis sollicitudin nisl. Nulla elit eros, semper eget tincidunt quis, egestas a nisl. Duis tempor tempus sapien consequat pellentesque. Cras vitae orci risus. Duis urna velit, interdum ac consectetur nec, condimentum non tellus. Sed nec nibh nisi. Cum sociis natoque penatibus et magnis dis parturient montes, nascetur ridiculus mus. Cras purus nulla, tincidunt quis placerat a, interdum at turpis. Pellentesque in lectus lacus. Sed at venenatis neque. 
      [published] => 2012-01-27 20:15:52 
      [tags] => Array 
       (
        [name] => 
        [slug] => 
       ) 

     ) 

    [1] => Array 
     (
      [title] => This is my first post! 
      [clean_title] => this-is-my-first-post 
      [body] => Lorem ipsum dolor sit amet, consectetur adipiscing elit. Phasellus eget est sit amet libero volutpat eleifend facilisis sollicitudin nisl. Nulla elit eros, semper eget tincidunt quis, egestas a nisl. Duis tempor tempus sapien consequat pellentesque. Cras vitae orci risus. Duis urna velit, interdum ac consectetur nec, condimentum non tellus. Sed nec nibh nisi. Cum sociis natoque penatibus et magnis dis parturient montes, nascetur ridiculus mus. Cras purus nulla, tincidunt quis placerat a, interdum at turpis. Pellentesque in lectus lacus. Sed at venenatis neque. 
      [published] => 2012-01-27 18:37:47 
      [tags] => Array 
       (
        [name] => programming 
        [slug] => programming 
       ) 

     ) 

    [2] => Array 
     (
      [title] => This is my first post! 
      [clean_title] => this-is-my-first-post 
      [body] => Lorem ipsum dolor sit amet, consectetur adipiscing elit. Phasellus eget est sit amet libero volutpat eleifend facilisis sollicitudin nisl. Nulla elit eros, semper eget tincidunt quis, egestas a nisl. Duis tempor tempus sapien consequat pellentesque. Cras vitae orci risus. Duis urna velit, interdum ac consectetur nec, condimentum non tellus. Sed nec nibh nisi. Cum sociis natoque penatibus et magnis dis parturient montes, nascetur ridiculus mus. Cras purus nulla, tincidunt quis placerat a, interdum at turpis. Pellentesque in lectus lacus. Sed at venenatis neque. 
      [published] => 2012-01-27 18:37:47 
      [tags] => Array 
       (
        [name] => android 
        [slug] => android 
       ) 

     ) 

    [3] => Array 
     (
      [title] => This is my first post! 
      [clean_title] => this-is-my-first-post 
      [body] => Lorem ipsum dolor sit amet, consectetur adipiscing elit. Phasellus eget est sit amet libero volutpat eleifend facilisis sollicitudin nisl. Nulla elit eros, semper eget tincidunt quis, egestas a nisl. Duis tempor tempus sapien consequat pellentesque. Cras vitae orci risus. Duis urna velit, interdum ac consectetur nec, condimentum non tellus. Sed nec nibh nisi. Cum sociis natoque penatibus et magnis dis parturient montes, nascetur ridiculus mus. Cras purus nulla, tincidunt quis placerat a, interdum at turpis. Pellentesque in lectus lacus. Sed at venenatis neque. 
      [published] => 2012-01-27 18:37:47 
      [tags] => Array 
       (
        [name] => windows 
        [slug] => windows 
       ) 

     ) 

) 

私はそれを見るように、代わりにポストのために各タグを返すので、それだけで別のタグでそのポストを複数返すています。私はそれが各投稿のtags配列がその投稿の各タグの要素を持つようにそれが必要です。

すべてのヘルプは非常に高く評価される:)

Answer 1

フィルターあなたはSQLからそれを取得した後、PHPレベルでのデータ：

public function getLatestPosts() 
{ 
    $query = $this->db->query('SELECT p_id, title, clean_title, body, published, name, slug 
           FROM posts 
           LEFT JOIN post_tags ON posts.p_id=post_tags.p_id 
           LEFT JOIN tags ON post_tags.t_id=tags.t_id 
           ORDER BY published DESC'); 
    $posts = array(); 
    foreach ($query->result() as $row) 
    { 
     if (!isset($posts[$row->p_id])) { 
      $posts[$row->p_id] = array('title' => $row->title, 
             'clean_title' => $row->clean_title, 
             'body' => $row->body, 
             'published' => $row->published, 
             'tags' => array()); 
     } 
     $posts[$row->p_id]['tags'][] = array('name' => $row->name, 
              'slug' => $row->slug); 
    } 
    print_r($posts); 
    return $posts; 
}