Question

我有一张表现金，其结构如下

现金

FileID     Cash   Date
1           50   03.04.2017
2           100  08.07.2015
3           70   14.09.2018

现在，我想添加一个新列，称为来源，以标识现金来自何处：

FileID     Cash   Date        Source
1           50   03.04.2017   Bank
2           100  08.07.2015   Natural Person
3           70   14.09.2018   Bank

要识别特定来源（例如“自然人”），我正在使用以下选择：

select y.*
from  

(select fileID,  date, cash, max(date_of_stage) as max_date
from (select c.fileID, c.date, c.cash, s.stage, s.date_of_stage  
      from cash c
      inner join stage s
      on c.fileID=s.fileID
      and s.date_of_stage < c.date
      ) 
group by fileID, date, cash ) x

inner join 

(select c.fileID, c.date, c.cash, s.stage, s.date_of_stage  
      from cash c
      inner join stage s
      on c.fileID=s.fileID) y

on x.fileID=y.fileID
and x.date=y.date
and x.cash=y.cash
and x.max_date=y.date_of_stage
where y.fileID is null

现在，我可以使用此选择来识别特定的来源，但是我不知道如何使用上述选择的数据来更新来源列。

我认为可能是这样的：

 update cash set Source = 'Natural Person' where 
 ( now I need to identify the c.fileID, c.date, c.cash from the above select somehow)

有什么提示吗？

Answer 1

查看此内容：

update cash set Source = 'Natural Person' from 
cash
inner join 
(select y.*
from  

(select fileID,  date, cash, max(date_of_stage) as max_date
from (select c.fileID, c.date, c.cash, s.stage, s.date_of_stage  
      from cash c
      inner join stage s
      on c.fileID=s.fileID
      and s.date_of_stage < c.date
      ) 
group by fileID, date, cash ) x

inner join 

(select c.fileID, c.date, c.cash, s.stage, s.date_of_stage  
      from cash c
      inner join stage s
      on c.fileID=s.fileID) y

on x.fileID=y.fileID
and x.date=y.date
and x.cash=y.cash
and x.max_date=y.date_of_stage
where y.fileID is null) m
on 
cash.fileID=m.fileID

使用select中的信息更新新创建的列-Oracle SQL

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