SQLite的：從多個表和合並列

我有另一種情況Select語句，我想併購一些列具有相同的父ID，但不同的子ID每個每一組，SQLite的：從多個表和合並列

這裏是我的表1;

+---------+----------+ 
|id_table1| value | 
+---------+----------+ 
| 1  | value1 | 
| 2  | value2 | 
| 3  | value3 | 
| 4  | value4 | 
| 5  | value5 | 
| 6  | value6 | 
| 7  | value7 | 
| 8  | value8 | 
| 9  | value9 | 
+---------+----------+

表2：

+---------+----------+ 
|id_table1| value | 
+---------+----------+ 
| P1 | valueP1 | 
| P2 | valueP2 | 
+---------+----------+

，這是我的關係表：

+---------+----------+---------+ 
|id_boss | id_child | answ | 
+---------+----------+---------+ 
| 1  |  2 | T | 
| 1  |  6 | F | 
| 2  |  P1 | T | 
| 2  |  4 | F | 
| 6  |  P2 | T | 
| 6  |  8 | F | 
+---------+----------+ --------+

，我期待的方式來組合列id_child

，其結果將是像這樣：

::編輯::

+---------+-----------+-----------+ 
|id_boss | child_T | child_F |  
+---------+-----------+-----------+ 
| value1 | value2 | value6 | 
| value2 | valueP1 | value4 | 
| value6 | valueP2 | value8 | 
+---------+-----------+-----------+

id_child第一排組id_boss是child_T
排和第二排組id_boss是child_F

來源

2014-05-11 user3599629

是否每個老闆有兩個孩子？也就是說，不應該將結果列稱爲「child_T」和「child_F」？ –

@cl忽略列answ，我只想顯示整個表， – user3599629

那麼它是如何確定哪個孩子進入第1列或第2列？ –

這是你想要的嗎？

SELECT (SELECT value FROM table1 WHERE table1.id_table1 = r1.id_boss) AS id_boss, 
     COALESCE((SELECT value FROM table1 WHERE table1.id_table1 = r1.id_child), 
       (SELECT value FROM table2 WHERE table2.id_table2 = r1.id_child) 
       ) AS child_T, 
     COALESCE((SELECT value FROM table1 WHERE table1.id_table1 = r2.id_child), 
       (SELECT value FROM table2 WHERE table2.id_table2 = r2.id_child) 
       ) AS child_F 
    FROM r_table AS r1 JOIN r_table AS r2 
    ON r1.id_boss = r2.id_boss AND r1.id_child <> r2.id_child AND r1.answ = 'T' 
;

測試here

來源

2014-05-11 15:10:20 josepn

是的，非常感謝 – user3599629

SQLite的：從多個表和合並列

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