我有一张按日期显示股票价格的表格,我想选择最接近多个日期的价值。例如,给我一个与今天,一个月前和两个月前最接近的价格。我可以在单独的语句中完成它,是否可以在单个语句中执行?
在下面,我想返回第1,2和6行作为最接近2 / 7,1 / 7和12/7日期(最好使用abs()这样做?)
+---+------------+---------+----------------+----------------+----------------+
| d | quotedate | price | 2018-02-07diff | 2018-01-07diff | 2017-12-07diff |
+---+------------+---------+----------------+----------------+----------------+
| 1 | 2018-02-06 | 13.796 | -1 | 30 | 61 |
| 2 | 2018-01-09 | 14.1135 | -29 | 2 | 33 |
| 3 | 2018-01-02 | 13.822 | -36 | -5 | 26 |
| 4 | 2017-12-27 | 13.7365 | -42 | -11 | 20 |
| 5 | 2017-12-22 | 13.75 | -47 | -16 | 15 |
| 6 | 2017-12-04 | 13.589 | -65 | -34 | -3 |
| 7 | 2017-11-28 | 13.477 | -71 | -40 | -9 |
| 8 | 2017-10-31 | 13.214 | -99 | -68 | -37 |
+---+------------+---------+----------------+----------------+----------------+
我已经让它做了一行,但是我希望能够一次完成所有3行吗? 小提琴:Here
答案 0 :(得分:1)
select p1.id, p1.name,
DATE_FORMAT(p1.quote_date, "%Y-%m-%d") as quotedate,
p1.price,
DATEDIFF( p1.quote_date, '2018-02-07' ) as 'diff1',
DATEDIFF( p1.quote_date, '2018-01-07' ) as 'diff2',
DATEDIFF( p1.quote_date, '2017-12-07' ) as 'diff3'
from prices p1
left outer join (select id, name, quote_date, price,
DATEDIFF( quote_date, '2018-02-07' ) as 'diff1p2'
FROM prices) p2
on (p1.name = p2.name
AND DATEDIFF( p1.quote_date, '2018-02-07' )< diff1p2
AND DATEDIFF( p1.quote_date, '2018-02-07' ) <=0
)
WHERE p1.name = 'Stock1'
AND p2.id is null
union
select p1.id, p1.name,
DATE_FORMAT(p1.quote_date, "%Y-%m-%d") as quotedate,
p1.price,
DATEDIFF( p1.quote_date, '2018-02-07' ) as 'diff1',
DATEDIFF( p1.quote_date, '2018-01-07' ) as 'diff2',
DATEDIFF( p1.quote_date, '2017-12-07' ) as 'diff3'
from prices p1
left outer join (select id, name, quote_date, price,
DATEDIFF( quote_date, '2018-01-07' ) as 'diff1p2'
FROM prices) p2
on (p1.name = p2.name
AND DATEDIFF( p1.quote_date, '2018-01-07' )< diff1p2
AND DATEDIFF( p1.quote_date, '2018-01-07' ) <=0
您应该在3个查询之间使用联合,以便一次获得所有3行