获取最小和最大日期
Get min and max dates
我有一组数据 (T-SQL 2012)，其中包含项目编号、orig_counter、prev_counter、start_date 和停止日期。我需要做的是获取最小值 start_date 和最大值 stop_date 如果该项目已从一个地方移动到另一个地方（prev_counter 将填充此 orig_counter移动。如果 prev_counter 为 0，则它没有先前的移动。
这是我的数据：
item orig_counter prev_counter start_date stop_date
---------------------------------------------------------------
AB108 8194 0 2001-12-03 2001-12-10
AB108 8569 0 2002-01-04 2002-01-22
AB108 9233 0 2002-02-01 2002-02-01
AB108 12365 0 2002-07-08 2004-02-29
AB108 24602 12365 2002-07-08 2004-03-09
AB108 24855 24602 2002-07-08 2004-03-23
AB108 24945 24855 2002-07-08 2004-03-29
AB108 25042 24945 2002-07-08 2004-04-04
AB108 25106 25042 2002-07-08 2004-04-11
AB108 25226 25106 2002-07-08 2004-04-22
AB108 25569 25226 2002-07-08 2004-04-28
AB108 25724 25569 2002-07-08 2004-06-01
AB108 26749 25724 2002-07-08 2004-06-30
AB108 27187 26749 2002-07-08 2004-07-11
AB108 27336 27187 2002-07-08 2004-08-15
AB108 28272 27336 2002-07-08 2004-08-24
AB108 28329 28272 2002-07-08 2004-11-07
AB108 29831 28329 2002-07-08 2004-11-08
AB108 30003 29831 2002-07-08 2005-08-03
AB108 36618 0 2005-09-19 2005-10-19
AB108 37613 0 2005-11-07 2005-11-07
AB108 37756 0 2005-11-10 2005-11-28
AB108 38979 0 2006-01-25 2006-08-01
如您所见，第 4 行 (orig_counter = 12365) 从该项目从一处移动到另一处的位置开始，直到倒数第 5 行 (orig_counter = 30003)。
所以我可以确定一个人拥有这个项目的时间长度，我需要得到这样的结果，其中我显示原始计数器、结束计数器（如果有的话）、最短开始日期和最长停止日期.
item orig_counter end_counter start_date stop_date
---------- ------------ ------------ ---------- ----------
AB108 8194 0 2001-12-03 2001-12-10
AB108 8569 0 2002-01-04 2002-01-22
AB108 9233 0 2002-02-01 2002-02-01
AB108 12365 30003 2002-07-08 2005-08-03
AB108 36618 0 2005-09-19 2005-10-19
AB108 37613 0 2005-11-07 2005-11-07
AB108 37756 0 2005-11-10 2005-11-28
AB108 38979 0 2006-01-25 2006-08-01
此查询递归循环遍历 orig_counter 和 prev_counter，从 prev_counter = 0:
开始
-- Sample data
declare @data table(item char(5), orig_counter int, prev_counter int, start_date datetime, stop_date datetime);
insert into @data(item, orig_counter, prev_counter, start_date, stop_date) values
('AB108', 8194, 0, '2001-12-03', '2001-12-10')
, ('AB108', 8569, 0, '2002-01-04', '2002-01-22')
, ('AB108', 9233, 0, '2002-02-01', '2002-02-01')
, ('AB108', 12365, 0, '2002-07-08', '2004-02-29')
, ('AB108', 24602, 12365, '2002-07-08', '2004-03-09')
, ('AB108', 24855, 24602, '2002-07-08', '2004-03-23')
, ('AB108', 24945, 24855, '2002-07-08', '2004-03-29')
, ('AB108', 25042, 24945, '2002-07-08', '2004-04-04')
, ('AB108', 25106, 25042, '2002-07-08', '2004-04-11')
, ('AB108', 25226, 25106, '2002-07-08', '2004-04-22')
, ('AB108', 25569, 25226, '2002-07-08', '2004-04-28')
, ('AB108', 25724, 25569, '2002-07-08', '2004-06-01')
, ('AB108', 26749, 25724, '2002-07-08', '2004-06-30')
, ('AB108', 27187, 26749, '2002-07-08', '2004-07-11')
, ('AB108', 27336, 27187, '2002-07-08', '2004-08-15')
, ('AB108', 28272, 27336, '2002-07-08', '2004-08-24')
, ('AB108', 28329, 28272, '2002-07-08', '2004-11-07')
, ('AB108', 29831, 28329, '2002-07-08', '2004-11-08')
, ('AB108', 30003, 29831, '2002-07-08', '2005-08-03')
, ('AB108', 36618, 0, '2005-09-19', '2005-10-19')
, ('AB108', 37613, 0, '2005-11-07', '2005-11-07')
, ('AB108', 37756, 0, '2005-11-10', '2005-11-28')
, ('AB108', 38979, 0, '2006-01-25', '2006-08-01');
-- Recursive query
with list(n, item, orig_counter, prev_counter, start_date, stop_date) as (
Select 0, item, orig_counter, orig_counter, start_date, stop_date From @data Where prev_counter = 0
Union All
Select l.n+1, l.item, l.orig_counter, d.orig_counter, l.start_date, d.stop_date From list as l
Inner Join @data as d on l.prev_counter = d.prev_counter and l.item= d.item
)
Select l.item, l.orig_counter, prev_counter = case when m.mx > 0 then l.prev_counter else 0 end, l.start_date, l.stop_date
From list l
Inner Join (Select mx = max(n), item, orig_counter From list Group By item, orig_counter) as m
On m.item = l.item and m.orig_counter = l.orig_counter and m.mx = l.n
Order By l.item, l.orig_counter
OPTION (MAXRECURSION 0);
输出：
item | orig_counter | prev_counter | start_date | stop_date
AB108 | 8194 | 0 | 2001-12-03 00:00:00.000 | 2001-12-10 00:00:00.000
AB108 | 8569 | 0 | 2002-01-04 00:00:00.000 | 2002-01-22 00:00:00.000
AB108 | 9233 | 0 | 2002-02-01 00:00:00.000 | 2002-02-01 00:00:00.000
AB108 | 12365 | 30003 | 2002-07-08 00:00:00.000 | 2005-08-03 00:00:00.000
AB108 | 36618 | 0 | 2005-09-19 00:00:00.000 | 2005-10-19 00:00:00.000
AB108 | 37613 | 0 | 2005-11-07 00:00:00.000 | 2005-11-07 00:00:00.000
AB108 | 37756 | 0 | 2005-11-10 00:00:00.000 | 2005-11-28 00:00:00.000
AB108 | 38979 | 0 | 2006-01-25 00:00:00.000 | 2006-08-01 00:00:00.000
我有一组数据 (T-SQL 2012)，其中包含项目编号、orig_counter、prev_counter、start_date 和停止日期。我需要做的是获取最小值 start_date 和最大值 stop_date 如果该项目已从一个地方移动到另一个地方（prev_counter 将填充此 orig_counter移动。如果 prev_counter 为 0，则它没有先前的移动。
这是我的数据：
item orig_counter prev_counter start_date stop_date
---------------------------------------------------------------
AB108 8194 0 2001-12-03 2001-12-10
AB108 8569 0 2002-01-04 2002-01-22
AB108 9233 0 2002-02-01 2002-02-01
AB108 12365 0 2002-07-08 2004-02-29
AB108 24602 12365 2002-07-08 2004-03-09
AB108 24855 24602 2002-07-08 2004-03-23
AB108 24945 24855 2002-07-08 2004-03-29
AB108 25042 24945 2002-07-08 2004-04-04
AB108 25106 25042 2002-07-08 2004-04-11
AB108 25226 25106 2002-07-08 2004-04-22
AB108 25569 25226 2002-07-08 2004-04-28
AB108 25724 25569 2002-07-08 2004-06-01
AB108 26749 25724 2002-07-08 2004-06-30
AB108 27187 26749 2002-07-08 2004-07-11
AB108 27336 27187 2002-07-08 2004-08-15
AB108 28272 27336 2002-07-08 2004-08-24
AB108 28329 28272 2002-07-08 2004-11-07
AB108 29831 28329 2002-07-08 2004-11-08
AB108 30003 29831 2002-07-08 2005-08-03
AB108 36618 0 2005-09-19 2005-10-19
AB108 37613 0 2005-11-07 2005-11-07
AB108 37756 0 2005-11-10 2005-11-28
AB108 38979 0 2006-01-25 2006-08-01
如您所见，第 4 行 (orig_counter = 12365) 从该项目从一处移动到另一处的位置开始，直到倒数第 5 行 (orig_counter = 30003)。
所以我可以确定一个人拥有这个项目的时间长度，我需要得到这样的结果，其中我显示原始计数器、结束计数器（如果有的话）、最短开始日期和最长停止日期.
item orig_counter end_counter start_date stop_date
---------- ------------ ------------ ---------- ----------
AB108 8194 0 2001-12-03 2001-12-10
AB108 8569 0 2002-01-04 2002-01-22
AB108 9233 0 2002-02-01 2002-02-01
AB108 12365 30003 2002-07-08 2005-08-03
AB108 36618 0 2005-09-19 2005-10-19
AB108 37613 0 2005-11-07 2005-11-07
AB108 37756 0 2005-11-10 2005-11-28
AB108 38979 0 2006-01-25 2006-08-01
此查询递归循环遍历 orig_counter 和 prev_counter，从 prev_counter = 0:
开始-- Sample data
declare @data table(item char(5), orig_counter int, prev_counter int, start_date datetime, stop_date datetime);
insert into @data(item, orig_counter, prev_counter, start_date, stop_date) values
('AB108', 8194, 0, '2001-12-03', '2001-12-10')
, ('AB108', 8569, 0, '2002-01-04', '2002-01-22')
, ('AB108', 9233, 0, '2002-02-01', '2002-02-01')
, ('AB108', 12365, 0, '2002-07-08', '2004-02-29')
, ('AB108', 24602, 12365, '2002-07-08', '2004-03-09')
, ('AB108', 24855, 24602, '2002-07-08', '2004-03-23')
, ('AB108', 24945, 24855, '2002-07-08', '2004-03-29')
, ('AB108', 25042, 24945, '2002-07-08', '2004-04-04')
, ('AB108', 25106, 25042, '2002-07-08', '2004-04-11')
, ('AB108', 25226, 25106, '2002-07-08', '2004-04-22')
, ('AB108', 25569, 25226, '2002-07-08', '2004-04-28')
, ('AB108', 25724, 25569, '2002-07-08', '2004-06-01')
, ('AB108', 26749, 25724, '2002-07-08', '2004-06-30')
, ('AB108', 27187, 26749, '2002-07-08', '2004-07-11')
, ('AB108', 27336, 27187, '2002-07-08', '2004-08-15')
, ('AB108', 28272, 27336, '2002-07-08', '2004-08-24')
, ('AB108', 28329, 28272, '2002-07-08', '2004-11-07')
, ('AB108', 29831, 28329, '2002-07-08', '2004-11-08')
, ('AB108', 30003, 29831, '2002-07-08', '2005-08-03')
, ('AB108', 36618, 0, '2005-09-19', '2005-10-19')
, ('AB108', 37613, 0, '2005-11-07', '2005-11-07')
, ('AB108', 37756, 0, '2005-11-10', '2005-11-28')
, ('AB108', 38979, 0, '2006-01-25', '2006-08-01');
-- Recursive query
with list(n, item, orig_counter, prev_counter, start_date, stop_date) as (
Select 0, item, orig_counter, orig_counter, start_date, stop_date From @data Where prev_counter = 0
Union All
Select l.n+1, l.item, l.orig_counter, d.orig_counter, l.start_date, d.stop_date From list as l
Inner Join @data as d on l.prev_counter = d.prev_counter and l.item= d.item
)
Select l.item, l.orig_counter, prev_counter = case when m.mx > 0 then l.prev_counter else 0 end, l.start_date, l.stop_date
From list l
Inner Join (Select mx = max(n), item, orig_counter From list Group By item, orig_counter) as m
On m.item = l.item and m.orig_counter = l.orig_counter and m.mx = l.n
Order By l.item, l.orig_counter
OPTION (MAXRECURSION 0);
输出：
item | orig_counter | prev_counter | start_date | stop_date
AB108 | 8194 | 0 | 2001-12-03 00:00:00.000 | 2001-12-10 00:00:00.000
AB108 | 8569 | 0 | 2002-01-04 00:00:00.000 | 2002-01-22 00:00:00.000
AB108 | 9233 | 0 | 2002-02-01 00:00:00.000 | 2002-02-01 00:00:00.000
AB108 | 12365 | 30003 | 2002-07-08 00:00:00.000 | 2005-08-03 00:00:00.000
AB108 | 36618 | 0 | 2005-09-19 00:00:00.000 | 2005-10-19 00:00:00.000
AB108 | 37613 | 0 | 2005-11-07 00:00:00.000 | 2005-11-07 00:00:00.000
AB108 | 37756 | 0 | 2005-11-10 00:00:00.000 | 2005-11-28 00:00:00.000
AB108 | 38979 | 0 | 2006-01-25 00:00:00.000 | 2006-08-01 00:00:00.000