Question

我有下表：

('cat', 5000, 7000, 'A'),
('dog', 9200, 11000, 'A'),
('fog', 6500, 9300, 'B'),
('fox', 16001, 15001, 'B'),
('cat', 5005, 7005, 'B'),
('dog', 9299, 11399, 'B'),
('cat', 5005, 7005, 'B'),
('dog', 9299, 11399, 'B'),
('fox', 16001, 15002, 'A')

我需要通过第一列获得选择组，然后通过以下总和获得4列：

标志的col2，

col3 for A flag，

B标志的col2和

col标志为B标志。

我怎么能得到这个？

SQLFiddle

Answer 1

SELECT
    Animal,
    SUM(CASE WHEN flg = 'A' THEN V1 ELSE 0 END) AS A_V1,
    SUM(CASE WHEN flg = 'A' THEN V2 ELSE 0 END) AS A_V2,
    SUM(CASE WHEN flg = 'B' THEN V1 ELSE 0 END) AS B_V1,
    SUM(CASE WHEN flg = 'B' THEN V2 ELSE 0 END) AS B_V2
FROM
    MyTab
GROUP BY
    Animal

Answer 2

select animal, 
    SUM(If(flg='A',V1,0)),
    SUM(If(flg='A',V2,0)),
    SUM(If(flg='B',V1,0)),
    SUM(If(flg='B',V2,0))
from MyTab
group by animal

SQL＆＃34;分裂＆＃34;通过...分组

2 个答案: