此GROUP BY查詢有什么問題？

Question

我似乎無法解決這個問題。 我閱讀的所有資源都表明可以這樣做：

'SELECT e.ID, e.EVENT_NAME, e.EVENT_DATE, v.VENUE_NAME, l.LOCATION, GROUP_CONCAT(ms.MUSIC_STYLE_NAME) as `Styles`'.
'FROM events AS e'.
'INNER JOIN venues as v ON e.VENUE_LOCATION = v.ID'.
'INNER JOIN locations AS l ON e.VENUE_LOCATION = l.ID'.
'INNER JOIN event_music_styles AS ems ON e.ID = ems.EVENT_ID'.
'INNER JOIN music_styles AS ms ON ms.ID = ems.MUSIC_STYLE_ID'.
'GROUP BY e.ID';

然而...

查詢無效：您的SQL語法有誤； 檢查與您的MySQL服務器版本相對應的手冊以獲取正確的語法，以在第1行的“ BY e.ID”附近使用

Answer 1

看來您錯過了空格。 嘗試

'SELECT e.ID, e.EVENT_NAME, e.EVENT_DATE, v.VENUE_NAME, l.LOCATION, GROUP_CONCAT(ms.MUSIC_STYLE_NAME) as `Styles`'.
     ' FROM events AS e'.
     ' INNER JOIN venues as v ON e.VENUE_LOCATION = v.ID'.
     ' INNER JOIN locations AS l ON e.VENUE_LOCATION = l.ID'.
     ' INNER JOIN event_music_styles AS ems ON e.ID = ems.EVENT_ID'.
     ' INNER JOIN music_styles AS ms ON ms.ID = ems.MUSIC_STYLE_ID'.
     ' GROUP BY e.ID';

Answer 2

我不確定這是什么語言，但似乎

'INNER JOIN music_styles AS ms ON ms.ID = ems.MUSIC_STYLE_ID'. 'GROUP BY e.ID'

會導致

'INNER JOIN music_styles AS ms ON ms.ID = ems.MUSIC_STYLE_IDGROUP BY e.ID'

因此無法識別“ group”關鍵字。

Answer 3

好吧，試試這個

SELECT e.ID,
       e.EVENT_NAME,
       e.EVENT_DATE,
       v.VENUE_NAME,
       l.LOCATION,
       GROUP_CONCAT(ms.MUSIC_STYLE_NAME) as `Styles`
       FROM events as e
         INNER JOIN venues as v ON e.VENUE_LOCATION = v.ID
         INNER JOIN locations as l ON e.VENUE_LOCATION = l.ID
         INNER JOIN event_music_styles as ems ON e.ID = ems.EVENT_ID
         INNER JOIN music_styles as ms ON ms.ID = ems.MUSIC_STYLE_ID
         GROUP BY e.ID;