在連接中獲取多行（codeigniter）

Question

我無法從下面的代碼中獲得我期望的結果。

第一步是：

從表中獲取一行，從另一個表中連接多行...... rsult數組應如下所示：

array(
  field_1, 
  field_2, 
  field_3, 
  joined_array(
    field_a_array(
      field_a_a, 
      field_a_b, 
      field_a_c
    ), 
    field_b_array(
      field_b_a, 
      field_b_b, 
      field_b_c
    )
  ) 
) 

我的查詢看起來像這樣：

（似乎where，join等位置對於codigniters db class來說並不重要）

$this->db->select('events.*, genres_x_events.*');

$this->db->from('events');
$this->db->where('events.slug', $slug);
$this->db->where('events.deleted', 0);

$this->db->join('genres_x_events', 'genres_x_events.event_slug = events.slug');

$query = $this->db->get();

我面臨的問題是，當我希望每個連接檢索多行時，我只從連接中獲取一行。

編輯：

last_query（）：

SELECT `events`.*, `genres_x_events`.`genre_slug`
FROM (`events`)
LEFT OUTER JOIN `genres_x_events` ON `genres_x_events`.`event_slug` = `events`.`slug`
WHERE `events`.`slug` =  'test'
AND `events`.`deleted` =  0

輸出：

Array(
    [0] => Array
        (
            [id] => 25
            [headline] => test
            [subheadline] => 
            [slug] => test
            [date] => 2012-08-10
            [start_time] => 00:00:00
            [end_time] => 00:00:00
            [price] => 
            [body] => 
            [location_id] => 5
            [genre_id] => 0
            [creation_date] => 2012-08-10 14:26:33
            [update_date] => 2012-08-10 14:26:41
            [deleted] => 0
            [genre_slug] => rock
        )

    [1] => Array
        (
            [id] => 25
            [headline] => test
            [subheadline] => 
            [slug] => test
            [date] => 2012-08-10
            [start_time] => 00:00:00
            [end_time] => 00:00:00
            [price] => 
            [body] => 
            [location_id] => 5
            [genre_id] => 0
            [creation_date] => 2012-08-10 14:26:33
            [update_date] => 2012-08-10 14:26:41
            [deleted] => 0
            [genre_slug] => metal
        )

    [2] => Array
        (
            [id] => 25
            [headline] => test
            [subheadline] => 
            [slug] => test
            [date] => 2012-08-10
            [start_time] => 00:00:00
            [end_time] => 00:00:00
            [price] => 
            [body] => 
            [location_id] => 5
            [genre_id] => 0
            [creation_date] => 2012-08-10 14:26:33
            [update_date] => 2012-08-10 14:26:41
            [deleted] => 0
            [genre_slug] => indie
        )

)

想要輸出（這樣的東西會很酷）：

Array(
    [0] => Array
        (
            [id] => 25
            [headline] => test
            [subheadline] => 
            [slug] => test
            [date] => 2012-08-10
            [start_time] => 00:00:00
            [end_time] => 00:00:00
            [price] => 
            [body] => 
            [location_id] => 5
            [genre_id] => 0
            [creation_date] => 2012-08-10 14:26:33
            [update_date] => 2012-08-10 14:26:41
            [deleted] => 0
            [genres] => Array(
                [0] => rock
                [1] => metal
                [2] => indie
            )
        )
)

Answer 1

嘗試通過event.id對其進行分組，然后使用group_concat，如下所示：

SELECT `events`.*, group_concat(`genres_x_events`.`genre_slug`)
FROM (`events`)
LEFT OUTER JOIN `genres_x_events` ON `genres_x_events`.`event_slug` = `events`.`slug`
WHERE `events`.`slug` =  'test'
AND `events`.`deleted` =  0
GROUP BY events.id

這將為您提供逗號分隔的給定event.id所有類型的列表。 您可以使用類似的方式更改分隔符（類似於管道）

SELECT `events`.*, group_concat(`genres_x_events`.`genre_slug` SEPARATOR '|')
FROM (`events`)
LEFT OUTER JOIN `genres_x_events` ON `genres_x_events`.`event_slug` = `events`.`slug`
WHERE `events`.`slug` =  'test'
AND `events`.`deleted` =  0
GROUP BY events.id