MySQL，將特定的行列合併到另一行

Question

你能幫忙找到解決方案嗎？

我有此查詢

SELECT P.id, P.url, PT.name, PT.lang 
FROM cms_pages P 
INNER JOIN cms_pages_translations PT 
    ON PT.page_id = P.id 
ORDER BY P.id DESC LIMIT 10; 

返回是這樣的：

ID |  URL  |  NAME  | LANGUAGE   
--------------------------------------------------- 
1 | 'hello-word' | 'Hello world' | 1 
--------------------------------------------------- 
1 | 'hello-word' | 'Hola mundo'  | 2 
--------------------------------------------------- 
1 | 'hello-word' | 'Olá mundo'  | 3 
--------------------------------------------------- 
2 | 'now-online' | 'We're online' | 1 
--------------------------------------------------- 
2 | 'now-online' | 'Estamos online' | 2 
--------------------------------------------------- 
2 | 'now-online' | 'Estamos online' | 3 

我如何能實現的東西看起來喜歡這樣的：

ID |  URL  |  NAME_1  |  NAME_2  | NAME_3 
----------------------------------------------------------------------------- 
1 | 'hello-word' | 'Hello world' | 'Hola mundo' | 'Olá mundo' 
----------------------------------------------------------------------------- 
2 | 'now-online' | 'We're online' | 'Estamos online' | 'Estamos online' 
----------------------------------------------------------------------------- 

Answer 1

如果你知道潛在語言的數量 - 這會導致瞭解額外列的數量 - 您可以e conditional aggregation。下面是基於關閉您的樣本數據的例子：

select id, url, 
    max(case when language = 1 then name end) name_1, 
    max(case when language = 2 then name end) name_2, 
    max(case when language = 3 then name end) name_3 
from <yourquery> 
group by id, url 

如果你不知道語言的數量，你將不得不使用dynamic sql建在飛行中的欄。