我有一张包含就业日期的表格。每次发生变化时都会添加一个新行 - 薪水的变化是最常见的变化。因此，新行等于该人的最后 TO 日期加一 (1)。如果我的薪水在 2014-04-01 发生变化，我的前一行将在 2013-03-31 结束其 TO 日期，而我的新行将开始其 FROM 日期为 2014-04-01。
我只想获取就业日期，而不是由于更改而导致的后续日期。看看这张表:
SSN FROM TO
----------------------------------
0987654321 2011-01-01 2011-12-31
0987654321 2012-01-01 2012-12-31
1234567890 2012-01-01 2012-12-31
0987654321 2013-01-01 2013-12-31
1234567890 2013-01-01 2013-06-30
0987654321 2014-01-01 2014-08-31
1234567890 2016-01-01 2016-12-31
1234567890 2017-01-01 2017-12-31
1234567890 2018-01-01 null
我想要的输出:
SSN FROM TO
----------------------------------
0987654321 2011-01-01 2014-08-31
1234567890 2012-01-01 2013-06-30
1234567890 2016-01-01 null
我想我可以创建一个比 TO 多一天的字段:
SELECT
SSN, TO, FROM, DATEADD(DAY, 1, TO) AS NEW
FROM
table
但我不知道如何在不同的行上继续匹配 NEW 和 TO。也许 WHERE NOT EXISTS 之类的？我不能让它工作。
然后我想我可以使用LAG但是默认情况下表中的上一行与下一行没有关系，我不能使用ORDER BY一个子查询。我不允许，不知道为什么(T-SQL？)。
仅供引用，我不能CREATE TABLE 或INSERT INTO TABLE 等，我也不能声明变量。我们将获得一个允许所有这些的模块，但现在我没有这些特权。
更新: 第一个答案实际上是正确的，但我注意到另一个干扰它的领域。一个 SSN 可以包含多个 ID，因此 ID 也必须拆分。这是我表中的实际数据。
CREATE TABLE Samples
(
SSN varchar(10),
ID varchar(4),
FromDate Date,
ToDate Date
);
INSERT INTO Samples
(SSN, ID, FromDate, ToDate)
VALUES
( '6612140000', '1000', '2005-01-01', '2005-03-31' ),
( '6612140000', '1000', '2005-04-01', '2005-09-30' ),
( '6612140000', '1000', '2005-10-01', '2006-03-31' ),
( '6612140000', '2000', '2005-10-01', '2006-04-30' ),
( '6612140000', '1000', '2006-04-01', '2007-03-31' ),
( '6612140000', '1000', '2007-04-01', '2008-03-31' ),
( '6612140000', '1000', '2008-04-01', '2009-03-31' ),
( '6612140000', '1000', '2009-04-01', '2010-03-31' ),
( '6612140000', '1000', '2010-04-01', '2010-11-30' ),
( '6612140000', '1000', '2010-12-01', '2011-03-31' ),
( '6612140000', '1000', '2011-04-01', '2011-08-21' ),
( '6612140000', '1000', '2011-08-22', '2011-11-13' ),
( '6612140000', '1000', '2011-11-14', '2011-11-30' ),
( '6612140000', '1000', '2011-12-01', '2012-01-31' ),
( '6612140000', '1000', '2016-07-01', '2017-03-31' ),
( '6612140000', '1000', '2017-04-01', '2017-11-30' ),
( '6612140000', '1000', '2017-12-01', '2018-03-31' ),
( '6612140000', '1000', '2018-04-01', null ),
( '7605140000', '1000', '2013-11-01', '2013-11-30' ),
( '7605140000', '1000', '2013-12-01', '2013-12-31' ),
( '7605140000', '1000', '2014-01-01', '2014-03-31' ),
( '7605140000', '1000', '2014-04-01', '2014-12-31' ),
( '7605140000', '1000', '2015-05-01', '2015-05-31' ),
( '7605140000', '1000', '2015-06-01', '2015-09-30' ),
( '7605140000', '1000', '2015-10-01', '2015-10-31' ),
( '7605140000', '1000', '2016-01-25', '2016-07-24' ),
( '7605140000', '1000', '2016-07-25', '2016-08-31' ),
( '7605140000', '1000', '2016-09-01', '2017-03-31' ),
( '7605140000', '1000', '2017-04-01', '2017-11-30' ),
( '7605140000', '1000', '2017-12-01', null );
答案中的代码，我尝试将 ID 字段添加到，但没有成功:
with
FromDates as (
-- All of the FromDates for each SSN for which there is not
-- a contiguous preceding period.
select SO.SSN, SO.ID, SO.FromDate, SO.ToDate,
Row_Number() over ( partition by SO.SSN order by SO.FromDate ) as RN
from Samples as SO
where not exists (
select 42 from Samples as SI where SI.SSN = SO.SSN and SI.ID = SO.ID and
SI.ToDate = DateAdd( day, -1, SO.FromDate ) ) ),
ToDates as (
-- All of the ToDates for each SSN for which there is not
-- a contiguous following period.
select SSN, ID, FromDate, ToDate, Row_Number() over ( partition by SSN order by FromDate ) as RN
from Samples as SO
where not exists (
select 42 from Samples as SI where SI.SSN = SO.SSN and SI.ID = SO.ID and
SI.FromDate = DateAdd( day, 1, SO.ToDate ) ) ),
Ranges as (
-- Pair the FromDate and ToDate entries for each SSN .
select F.SSN, F.ID, F.FromDate, T.ToDate
from FromDates as F inner join
ToDates as T on T.SSN = F.SSN and T.ID = F.ID and T.RN = F.RN )
-- Use any ONE of the following select statements to see what is going on:
-- select * from FromDates
-- select * from ToDates
select * from Ranges
-- where SSN = '6612140000'
order by SSN, ID, FromDate
返回:
SSN ID FromDate ToDate
6612140000 1000 2016-07-01 (null)
7605140000 1000 2013-11-01 2014-12-31
7605140000 1000 2014-03-01 2014-12-31
7605140000 1000 2015-05-01 2015-10-31
7605140000 1000 2015-05-01 2015-10-31
7605140000 1000 2016-01-25 (null)
最佳答案
以下示例根据您的数据组装岛屿。通过更改启用/注释的最终 select 语句，您可以看到过程中的中间结果。
更新:更改了 CTE 中的日期比较，以便它们可以受益于 SSN, FromDate 和 SSN, ToDate 的索引。
-- Sample data.
declare @Samples table ( SSN VarChar(10), FromDate Date, ToDate Date );
insert into @Samples ( SSN, FromDate, ToDate ) values
( '0987654321', '2011-01-01', '2011-12-31' ),
( '0987654321', '2012-01-01', '2012-12-31' ),
( '1234567890', '2012-01-01', '2012-12-31' ),
( '0987654321', '2013-01-01', '2013-12-31' ),
( '1234567890', '2013-01-01', '2013-06-30' ),
( '0987654321', '2014-01-01', '2014-08-31' ),
( '1234567890', '2016-01-01', '2016-12-31' ),
( '1234567890', '2017-01-01', '2017-12-31' ),
( '1234567890', '2018-01-01', null );
select *
from @Samples;
-- Sample data made a little easier to read.
select *,
case when exists (
select 42 from @Samples as SI where SI.SSN = S.SSN and
DateDiff( day, S.ToDate, SI.FromDate ) = 1 ) then 1 else 0 end as Continued
from @Samples as S
order by SSN, FromDate;
-- Process the data.
with
FromDates as (
-- All of the FromDates for each SSN for which there is not
-- a contiguous preceding period.
select SO.SSN, SO.FromDate, SO.ToDate,
Row_Number() over ( partition by SO.SSN order by SO.FromDate ) as RN
from @Samples as SO
where not exists (
select 42 from @Samples as SI where SI.SSN = SO.SSN and
SI.ToDate = DateAdd( day, -1, SO.FromDate ) ) ),
ToDates as (
-- All of the ToDates for each SSN for which there is not
-- a contiguous following period.
select SSN, FromDate, ToDate, Row_Number() over ( partition by SSN order by FromDate ) as RN
from @Samples as SO
where not exists (
select 42 from @Samples as SI where SI.SSN = SO.SSN and
SI.FromDate = DateAdd( day, 1, SO.ToDate ) ) ),
Ranges as (
-- Pair the FromDate and ToDate entries for each SSN .
select F.SSN, F.FromDate, T.ToDate
from FromDates as F inner join
ToDates as T on T.SSN = F.SSN and T.RN = F.RN )
-- Use any ONE of the following select statements to see what is going on:
-- select * from FromDates order by SSN, FromDate;
-- select * from ToDates order by SSN, FromDate;
select * from Ranges order by SSN, FromDate;
当然，如果 SSN 中实际上有单独的 Id 值，这些值将被独立处理，答案将变为如下内容:
-- Sample data.
declare @Samples as Table ( SSN VarChar(10), Id VarChar(4), FromDate Date, ToDate Date );
insert into @Samples ( SSN, ID, FromDate, ToDate ) values
( '6612140000', '1000', '2005-01-01', '2005-03-31' ),
( '6612140000', '1000', '2005-04-01', '2005-09-30' ),
( '6612140000', '1000', '2005-10-01', '2006-03-31' ),
( '6612140000', '2000', '2005-10-01', '2006-04-30' ),
( '6612140000', '1000', '2006-04-01', '2007-03-31' ),
( '6612140000', '1000', '2007-04-01', '2008-03-31' ),
( '6612140000', '1000', '2008-04-01', '2009-03-31' ),
( '6612140000', '1000', '2009-04-01', '2010-03-31' ),
( '6612140000', '1000', '2010-04-01', '2010-11-30' ),
( '6612140000', '1000', '2010-12-01', '2011-03-31' ),
( '6612140000', '1000', '2011-04-01', '2011-08-21' ),
( '6612140000', '1000', '2011-08-22', '2011-11-13' ),
( '6612140000', '1000', '2011-11-14', '2011-11-30' ),
( '6612140000', '1000', '2011-12-01', '2012-01-31' ),
( '6612140000', '1000', '2016-07-01', '2017-03-31' ),
( '6612140000', '1000', '2017-04-01', '2017-11-30' ),
( '6612140000', '1000', '2017-12-01', '2018-03-31' ),
( '6612140000', '1000', '2018-04-01', null ),
( '7605140000', '1000', '2013-11-01', '2013-11-30' ),
( '7605140000', '1000', '2013-12-01', '2013-12-31' ),
( '7605140000', '1000', '2014-01-01', '2014-03-31' ),
( '7605140000', '1000', '2014-03-01', '2014-12-31' ),
( '7605140000', '1000', '2014-04-01', '2014-12-31' ),
( '7605140000', '1000', '2015-05-01', '2015-05-31' ),
-- ( '7605140000', '1000', '2015-05-01', '2015-05-31' ), -- Duplicate row?!
( '7605140000', '1000', '2015-06-01', '2015-09-30' ),
-- ( '7605140000', '1000', '2015-06-01', '2015-09-30' ), -- Duplicate row?!
( '7605140000', '1000', '2015-10-01', '2015-10-31' ),
-- ( '7605140000', '1000', '2015-10-01', '2015-10-31' ), -- Duplicate row?!
( '7605140000', '1000', '2016-01-25', '2016-07-24' ),
( '7605140000', '1000', '2016-07-25', '2016-08-31' ),
( '7605140000', '1000', '2016-09-01', '2017-03-31' ),
( '7605140000', '1000', '2017-04-01', '2017-11-30' ),
( '7605140000', '1000', '2017-12-01', null );
select *
from @Samples;
-- Sample data made a little easier to read.
select *,
case when exists (
select 42 from @Samples as SI where SI.SSN = S.SSN and SI.Id = S.Id and
DateDiff( day, S.ToDate, SI.FromDate ) = 1 ) then 1 else 0 end as Continued
from @Samples as S
order by SSN, Id, FromDate;
-- Process the data.
with
FromDates as (
-- All of the FromDates for each SSN for which there is not
-- a contiguous preceding period.
select SO.SSN, SO.Id, SO.FromDate, SO.ToDate,
Row_Number() over ( partition by SO.SSN, SO.Id order by SO.FromDate ) as RN
from @Samples as SO
where not exists (
select 42 from @Samples as SI where SI.SSN = SO.SSN and SI.Id = SO.Id and
SI.ToDate = DateAdd( day, -1, SO.FromDate ) ) ),
ToDates as (
-- All of the ToDates for each SSN for which there is not
-- a contiguous following period.
select SO.SSN, SO.Id, SO.FromDate, SO.ToDate,
Row_Number() over ( partition by SSN, SO.Id order by FromDate ) as RN
from @Samples as SO
where not exists (
select 42 from @Samples as SI where SI.SSN = SO.SSN and SI.Id = SO.Id and
SI.FromDate = DateAdd( day, 1, SO.ToDate ) ) ),
Ranges as (
-- Pair the FromDate and ToDate entries for each SSN .
select F.SSN, F.Id, F.FromDate, T.ToDate
from FromDates as F inner join
ToDates as T on T.SSN = F.SSN and T.Id = F.Id and T.RN = F.RN )
-- Use any ONE of the following select statements to see what is going on:
-- select * from FromDates order by SSN, Id, FromDate;
-- select * from ToDates order by SSN, Id, FromDate;
select * from Ranges order by SSN, Id, FromDate;
关于mysql - 查找第一次出现的连续开始/结束列，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/50310449/