使用子查询 (Oracle) 更新表

Question

我的表结构如下：

    HID            TIME_FROM         LAG_TIME_FROM          TIME_UNTIL
-------------------------------------------------------------------------
AAAAA12334566   06.07.19 04:04:51   13.07.19 04:05:17   13.07.19 04:05:17
AAAAA12334566   13.07.19 04:05:17   14.07.19 04:05:30   14.07.19 04:05:30
AAAAA12334566   14.07.19 04:05:30   23.07.19 22:00:00   23.07.19 22:00:00
AAAAA12334566   23.07.19 22:00:00   23.07.19 22:00:00   25.07.19 04:05:06
AAAAA12334566   23.07.19 22:00:00   25.07.19 04:05:06   22.07.19 22:00:00
AAAAA12334566   25.07.19 04:05:06   25.07.19 04:05:06   01.01.99 00:00:00
AAAAA12334566   25.07.19 04:05:06   01.01.99 00:00:00   24.07.19 04:05:06
BBBBBB12334566  29.06.18 14:59:20   01.02.19 14:25:00   01.02.19 14:25:00
BBBBBB12334566  01.02.19 14:25:00   07.03.19 04:07:48   07.03.19 04:07:48
BBBBBB12334566  07.03.19 04:07:48   05.07.19 04:04:47   09.07.19 04:04:52
BBBBBB12334566  05.07.19 04:04:47   06.07.19 04:04:51   09.07.19 04:04:52
BBBBBB12334566  06.07.19 04:04:51   08.07.19 13:00:45   09.07.19 04:04:52
BBBBBB12334566  08.07.19 13:00:45   08.07.19 13:18:19   12.07.19 04:04:44

我的表中存在HID、TIME_FROM 和TIME_UNTIL 列。 LAG_TIME_FROM 列由以下 SQL 语句生成，在表中不存在：

Select HID, TIME_FROM, nvl(lead(TIME_FROM) over(partition by HID order by TIME_FROM),timestamp '9999-01-01 00:00:00')  LAG_TIME_FROM, TIME_UNTIL
from my_table
where HID in (

' AAAAA12334566 ',
' BBBBBB12334566 ',
' CCCCCC12334566 ',
' DDDDD12334566 ',
'EEEEEEE12334566 ',
'GGGGG12334566 ');

我要做的是通过上面写的sql语句（LAG_TIME_FROM）更新TIME_UNTIL列。这是我的尝试：

    UPDATE my_table s1
    SET TIME_UNTIL= ( 

    select LAG_TIME_FROM from(
    select HID, TIME_FROM, nvl(lead(TIME_FROM) over(partition by HID order by TIME_FROM),timestamp '9999-01-01 00:00:00')  LAG_TIME_FROM, TIME_UNTIL
    from my_table
    ) s2 
    Where s1.HID in (
    ' AAAAA12334566 ',
    ' BBBBBB12334566 ',
    ' CCCCCC12334566 ',
    ' DDDDD12334566 ',
    'EEEEEEE12334566 ',
    'GGGGG12334566 ')
    and s1. hid = s2. hid
    and s1. TIME_FROM = s2.TIME_FROM
    and s1. TIME_UNTIL = s2. TIME_UNTIL
    );

但是当我运行代码时出现以下错误：

ORA-01407: 无法将 TIME_UNTIL 更新为 NULL。

我不明白为什么会得到 NULLS，因为当我运行 sql 语句时：

Select HID, TIME_FROM, nvl(lead(TIME_FROM) over(partition by HID order by TIME_FROM),timestamp '9999-01-01 00:00:00')  LAG_TIME_FROM, TIME_UNTIL
    from my_table
    where HID in (

    ' AAAAA12334566 ',
    ' BBBBBB12334566 ',
    ' CCCCCC12334566 ',
    ' DDDDD12334566 ',
    'EEEEEEE12334566 ',
    'GGGGG12334566 ');

一切看起来都很好

Answer 1

将nvl()（或者我喜欢的coalesce()）移到子查询之外：

UPDATE my_table s1
    SET TIME_UNTIL = coalesce((select LAG_TIME_FROM
                               from (select t.*,
                                            lead(TIME_FROM) over(partition by HID order by TIME_FROM) as LAG_TIME_FROM
                                     from my_table t
                                    ) s2 
                               where s1.hid = s2. hid and
                                     s1.TIME_FROM = s2.TIME_FROM and
                                     s1. TIME_UNTIL = s2.TIME_UNTIL
                              ), timestamp '9999-01-01 00:00:00'
                             )
where s1.HID in (' AAAAA12334566 ',
                 ' BBBBBB12334566 ',
                 ' CCCCCC12334566 ',
                 ' DDDDD12334566 ',
                 'EEEEEEE12334566 ',
                 'GGGGG12334566 '
                );

Answer 2

只需在更新语句中的外部选择后添加一个条件

     where LAG_TIME_FROM IS NOT 
    NULL

Answer 3

未格式化，阅读困难，我稍微格式化了一下。

UPDATE my_table s1
  SET TIME_UNTIL = 
    (select LAG_TIME_FROM 
     from (select HID, 
                  TIME_FROM, 
                  nvl(lead(TIME_FROM) over(partition by HID order by TIME_FROM), 
                      timestamp '9999-01-01 00:00:00'
                     ) LAG_TIME_FROM, 
                     TIME_UNTIL
           from my_table
          ) s2 
     Where s1.HID in (' AAAAA12334566 ',    --> are there really leading and
                      ' BBBBBB12334566 ',   --> trailing spaces here?
                      ' CCCCCC12334566 ',
                      ' DDDDD12334566 ',
                      'EEEEEEE12334566 ',
                      'GGGGG12334566 '
                     )
       and s1. hid = s2. hid                --> there shouldn't be any space between alias and
       and s1. TIME_FROM = s2.TIME_FROM     --> column names
       and s1. TIME_UNTIL = s2. TIME_UNTIL
    );

IN 元素中真的有前导和尾随空格吗？

除此之外，您似乎只想更新一些 s1 行，但您的查询正在更新 所有 行 - 其中一些更新为 NULL，因此 Oracle 抱怨列为最有可能声明为NOT NULL。

这意味着您必须限制要更新的行。也许将IN 子句移出子查询会有所帮助，例如

UPDATE my_table s1
  SET TIME_UNTIL = 
    (select LAG_TIME_FROM 
     from (select HID, 
                  TIME_FROM, 
                  nvl(lead(TIME_FROM) over(partition by HID order by TIME_FROM), 
                      timestamp '9999-01-01 00:00:00'
                     ) LAG_TIME_FROM, 
                     TIME_UNTIL
           from my_table
          ) s2 
     where 1 = 1                            --> placeholder for now missing IN clause
       and s1.hid = s2. hid                
       and s1.TIME_FROM = s2.TIME_FROM     
       and s1.TIME_UNTIL = s2. TIME_UNTIL
    )
Where s1.HID in (' AAAAA12334566 ',    --> are there really leading and
                 ' BBBBBB12334566 ',   --> trailing spaces here?
                 ' CCCCCC12334566 ',
                 ' DDDDD12334566 ',
                 'EEEEEEE12334566 ',
                 'GGGGG12334566 '
                );

看看有没有帮助；如果没有，你将不得不修复它。如何？你应该知道，你有数据。 EXISTS 子句通常在这种情况下会有所帮助。