日期作爲列（每天創建報告）

Question

我有這個查詢生成我想要的結果。 我只需要製造日期爲列

SELECT item, date, SUM(quantity) 
FROM t 
WHERE date between '2015-08-18' and '2015-08-20' 
GROUP BY item, date 

這裏是我的SQL FIDDLE

產生

結果我想

任何人都可以給我至少想法如何實現我想要的結果？

Answer 1

像這樣使用conditional Aggregate

要提取day從date使用DAY()功能

SELECT item, 
     SUM(case when day(date) = 18 then quantity else 0 end) as `18`, 
     SUM(case when day(date) = 19 then quantity else 0 end) as `19`, 
     SUM(case when day(date) = 20 then quantity else 0 end) as `20` 
FROM t 
WHERE date between '2015-08-18' and '2015-08-20' 
GROUP BY item 

SQL FIDDLE DEMO