如何使用SQL SELECT根据另一个表中的特定行查询表
有一个包含多个团队数据的表,如下所示:如何使用SQL SELECT根据另一个表中的特定行查询表,sql,presto,Sql,Presto,有一个包含多个团队数据的表,如下所示: original_dates: date | team_id | value --------------------------------- 2019-01-01 | 1 | 13 2019-01-01 | 2 | 88 2019-01-02 | 1 | 17 2019-01-02 | 2 | 99 2019-01-03
original_dates:
date | team_id | value
---------------------------------
2019-01-01 | 1 | 13
2019-01-01 | 2 | 88
2019-01-02 | 1 | 17
2019-01-02 | 2 | 99
2019-01-03 | 1 | 26
2019-01-03 | 2 | 105
2019-01-04 | 1 | 49
2019-01-04 | 2 | 134
2019-01-04 | 1 | 56
2019-01-04 | 2 | 167
但是,在某个日期,我们希望将该日期的值重置为0,将该ID的所有先前日期设置为0,然后从所有后续日期中减去该值,最小值为0。以下是需要重置的日期表:
inflection_dates:
date | team_id | value
-----------------------------------
2019-01-02 | 2 | 99
2019-01-03 | 1 | 26
这是我希望得到的结果表:
result:
date | team_id | value
---------------------------------
2019-01-01 | 1 | 0
2019-01-01 | 2 | 0
2019-01-02 | 1 | 0
2019-01-02 | 2 | 0 <- row in inflection_dates (value was 99)
2019-01-03 | 1 | 0 <- row in inflection_dates (value was 26)
2019-01-03 | 2 | 6 (-99)
2019-01-04 | 1 | 23 (-26)
2019-01-04 | 2 | 35 (-99)
2019-01-04 | 1 | 30 (-26)
2019-01-04 | 2 | 68 (-99)
唯一的限制是所有表都是只读的,所以我只能查询它们,不能修改它们
有人知道这是否可能吗 试试这个:
drop table #tmp
---------------------------------
select '2019-01-01' as date, 1 as team_id, 13 as value into #tmp
union select '2019-01-01', 2, 88
union select '2019-01-02', 1, 17
union select '2019-01-02', 2, 99
union select '2019-01-03', 1, 26
union select '2019-01-03', 2, 105
union select '2019-01-04', 1, 49
union select '2019-01-04', 2, 134
union select '2019-01-04', 1, 56
union select '2019-01-04', 2, 167
drop table #tmpinflection
---------------------------------
select '2019-01-02' as date, 2 as team_id, 99 as value into #tmpinflection
union select '2019-01-03', 1, 26
select a.date, a.team_id,
case when a.date <= b.date then 0
else a.value - b.value end as value
from #tmp a left join #tmpinflection b on a.team_id = b.team_id where b.date is not null
试试这个:
drop table #tmp
---------------------------------
select '2019-01-01' as date, 1 as team_id, 13 as value into #tmp
union select '2019-01-01', 2, 88
union select '2019-01-02', 1, 17
union select '2019-01-02', 2, 99
union select '2019-01-03', 1, 26
union select '2019-01-03', 2, 105
union select '2019-01-04', 1, 49
union select '2019-01-04', 2, 134
union select '2019-01-04', 1, 56
union select '2019-01-04', 2, 167
drop table #tmpinflection
---------------------------------
select '2019-01-02' as date, 2 as team_id, 99 as value into #tmpinflection
union select '2019-01-03', 1, 26
select a.date, a.team_id,
case when a.date <= b.date then 0
else a.value - b.value end as value
from #tmp a left join #tmpinflection b on a.team_id = b.team_id where b.date is not null
使用表的联接和CASE表达式计算新值:
select o.date, o.team_id,
case
when o.date <= i.date then 0
else o.value - i.value
end value
from original_dates o inner join inflection_dates i
on i.team_id = o.team_id
使用表的联接和CASE表达式计算新值:
select o.date, o.team_id,
case
when o.date <= i.date then 0
else o.value - i.value
end value
from original_dates o inner join inflection_dates i
on i.team_id = o.team_id
非常感谢。这帮了大忙谢谢你!这帮了大忙