如何將結果與條件分組？

Question

我無法解決這個問題很多小時。
這是我的表

t1: 

––––––––––––––––––––––––––––––––––– 
| id | text | lang | transl_id | 
––––––––––––––––––––––––––––––––––– 
| 1 | first | en | 222  | 
––––––––––––––––––––––––––––––––––– 
| 2 | second | de | 222  | 
––––––––––––––––––––––––––––––––––– 
| 3 | jkj | de | 234  | 
––––––––––––––––––––––––––––––––––– 
| 4 | 89080 | de | 235  | 
––––––––––––––––––––––––––––––––––– 

這裏是我的查詢：

SELECT 
    transl_id AS property, 
    (SELECT text FROM t1 WHERE lang='en') AS value1, 
    (SELECT text FROM t1 WHERE lang='de') AS value2, 

FROM t1 

它返回如下表：

––––––––––––––––––––––––––––––––––– 
| property | value1 | value2 | 
––––––––––––––––––––––––––––––––––– 
| 222 | first |   | 
––––––––––––––––––––––––––––––––––– 
| 222 |   | second | 
––––––––––––––––––––––––––––––––––– 
| 234 | jkj  |   | 
––––––––––––––––––––––––––––––––––– 
| 235 | 89080 |   | 
––––––––––––––––––––––––––––––––––– 

每行有兩種value1或value2，不可能兼顧。有沒有辦法對結果進行分組，以便property字段的值相等的行將在一行中？我的意思是這樣的：

––––––––––––––––––––––––––––––––––– 
| property | value1 | value2 | 
––––––––––––––––––––––––––––––––––– 
| 222 | first | second | 
––––––––––––––––––––––––––––––––––– 
... 

Answer 1

嘗試此查詢：

SELECT 
    property, 
    max(value1) as Value1, 
    max(value2) as Value2 
FROM 
(
SELECT transl_id AS property, 
    CASE when lang = 'en' then text else null end as value1, 
    CASE when lang = 'de' then text else null end as value2 
FROM t1 
) t 
GROUP BY property 

See this SQLFiddle

試圖在表中增加更多的價值，並得到期望的結果in this SQLFiddle.

Answer 2

也許是這樣的：

select t1.property, t1.value1, t2.value2 from 
(select property, value1 from table1 where value1 is not null) t1, 
(select property, value2 from table1 where value2 is not null) t2 
where t1.property = t2.property