Question

使用这一个查询和一些提示/建议遇到一点头痛将不胜感激。我找不到任何与我的问题真正相关的东西 - 我在传递闭包上找到了一些东西，这不是我需要的东西，因为我的数据可能会创建一个循环/循环，我认为会导致递归调用无限循环

假设我有两个基本表，其下方显示数据。完全披露：成员资格表是一个CTE，它已经完成了一些逻辑来计算 CServiceDate 列值。转移表是一个实际的表格，除了PK和 FromMembershipID 和 ToMembershipID 关系之外，它不包含任何其他内容。

成员

 
+==========+==============+================+==============+
| PersonID | MemberShipID | MembershipDate | CServiceDate |
+==========+==============+================+==============+
|        1 |           15 | Aug-01-2016    | Aug-27-2017  |
+----------+--------------+----------------+--------------+
|        1 |           16 | Mar-25-2016    | Sep-01-2000  |
+----------+--------------+----------------+--------------+
|        1 |           17 | Dec-06-2011    | May-15-1995  |
+----------+--------------+----------------+--------------+
|        1 |           18 | Jan-12-2009    | Feb-28-1998  |
+----------+--------------+----------------+--------------+
|        1 |           19 | Apr-08-2016    | Jul-10-1994  |
+----------+--------------+----------------+--------------+
|        1 |           20 | Jun-11-2010    | Nov-12-1997  |
+----------+--------------+----------------+--------------+

转移

+=====+=====+==================+================+
| TID | PID | FromMembershipID | ToMembershipID |
+=====+=====+==================+================+
|   1 |   1 |               16 |            15  |
+-----+-----+------------------+----------------+
|   2 |  1  |               18 |             17 |
+-----+-----+------------------+----------------+
|   3 |   1 |               19 |            17  |
+-----+-----+------------------+----------------+
|   4 |   1 |               20 |            18  |
+-----+-----+------------------+----------------+
|   5 |   1 |               20 |            19  |
+-----+-----+------------------+----------------+

问题我需要查询的是成员资格CTE中的每一行（即每个MembershipID），我想为所有相关的MembershipID返回MIN CServiceDate。我将此MIN值称为ECSD（预期信用服务日期）。 ECSD的计算只有两个条件：

如果会员记录通过查看FromMembershipID和ToMembershipID列，通过转移表以某种方式与当前的MembershipID相关联，则会将其视为与当前MembershipID“相关”。例如对于MembershipID 20，如果我们查看转移表，我们可以看到MembershipIDs 20,19,18和17都是通过传递性相关的（除了：通过转移）表，我们可以看到MembershipIDs 15和16彼此相关，但不是[20,19,18,17]）
在上面直接派生的与传递相关的会员资格列表中，在计算ECSD时可以在传递关系列表中考虑的唯一成员资格是MembershipDate比当前MembershipID更早的成员资格。例如根据给定MembershipID和转移表的MembershipDates，如果查看MembershipID 17，则在计算MembershiID 17的ECSD时不能考虑MembershipID 19，因为MembershipID 19具有MembershipDate（2016年4月8日））不早于MembershipID 17（2011年12月6日）

ECSD列的

预期输出

+==========+==============+================+==============+=============+
| PersonID | MemberShipID | MembershipDate | CServiceDate |    ECSD     |
+==========+==============+================+==============+=============+
|        1 |           15 | Aug-01-2016    | Aug-27-2017  | Sep-01-2000 |
+----------+--------------+----------------+--------------+-------------+
|        1 |           16 | Mar-25-2016    | Sep-01-2000  | Sep-01-2000 |
+----------+--------------+----------------+--------------+-------------+
|        1 |           17 | Dec-06-2011    | May-15-1995  | May-15-1995 |
+----------+--------------+----------------+--------------+-------------+
|        1 |           18 | Jan-12-2009    | Feb-28-1998  | Feb-28-1998 |
+----------+--------------+----------------+--------------+-------------+
|        1 |           19 | Apr-08-2016    | Jul-10-1994  | Jul-10-1994 |
+----------+--------------+----------------+--------------+-------------+
|        1 |           20 | Jun-11-2010    | Nov-12-1997  | Nov-12-1997 |
+----------+--------------+----------------+--------------+-------------+

请注意：

MembershipID可以在FromMembershipID和ToMembershipID列中显示倍数。这些列值不必是唯一的。
上面提供的表格是简单的关系。成员资格/转移可以只有1层深度（即1次转移）到N层深度，其中转移（如果仅通过查看From / ToMembershipID）可以创建循环循环。以下是更深层次转移关系的示例。
可能有帮助注意，如果TOMembershipID列中不存在MembershipID，则该MembershipID最早（可能有多个）。同样，如果FromMembershipID列中不存在MembershipID，则它是最终成员和最新成员。
- 可能存在一些块或一组转移，它们将某些成员资格关联在一起，但不是全部。

示例2

成员

+==========+==============+================+==============+
| personid | membershipid | membershipdate | CServiceDate |
+==========+==============+================+==============+
|   499510 |       548426 | 2014-09-29     | 2014-09-29   |
+----------+--------------+----------------+--------------+
|   499510 |       548428 | 2014-01-29     | 2014-01-29   |
+----------+--------------+----------------+--------------+
|   499510 |       548425 | 2012-05-28     | 2012-05-28   |
+----------+--------------+----------------+--------------+
|   499510 |       548429 | 2011-11-23     | 2011-11-23   |
+----------+--------------+----------------+--------------+
|   499510 |       548427 | 2008-07-03     | 2008-07-03   |
+----------+--------------+----------------+--------------+
|   499510 |       548431 | 2001-05-01     | 1976-01-01   |
+----------+--------------+----------------+--------------+
|   499510 |       548430 | 1998-10-08     | 1998-10-08   |
+----------+--------------+----------------+--------------+

传输

+=======+========+==================+================+
|  tid  |  pid   | FromMembershipID | ToMembershipID |
+=======+========+==================+================+
| 10664 | 499510 |           548430 |         548431 |
+-------+--------+------------------+----------------+
| 10665 | 499510 |           548431 |         548427 |
+-------+--------+------------------+----------------+
| 10666 | 499510 |           548427 |         548429 |
+-------+--------+------------------+----------------+
| 10667 | 499510 |           548429 |         548425 |
+-------+--------+------------------+----------------+
| 10668 | 499510 |           548425 |         548428 |
+-------+--------+------------------+----------------+
| 10669 | 499510 |           548428 |         548426 |
+-------+--------+------------------+----------------+
| 13085 | 499510 |           548430 |         548427 |
+-------+--------+------------------+----------------+
| 13086 | 499510 |           548427 |         548425 |
+-------+--------+------------------+----------------+
| 13087 | 499510 |           548425 |         548426 |
+-------+--------+------------------+----------------+
| 13088 | 499510 |           548431 |         548429 |
+-------+--------+------------------+----------------+
| 13089 | 499510 |           548429 |         548428 |
+-------+--------+------------------+----------------+

预期结果

+==========+==============+================+==============+============+
| personid | membershipid | membershipdate | CServiceDate |    ECSD    |
+==========+==============+================+==============+============+
|   499510 |       548426 | 2014-09-29     | 2014-09-29   | 1976-01-01 |
+----------+--------------+----------------+--------------+------------+
|   499510 |       548428 | 2014-01-29     | 2014-01-29   | 1976-01-01 |
+----------+--------------+----------------+--------------+------------+
|   499510 |       548425 | 2012-05-28     | 2012-05-28   | 1976-01-01 |
+----------+--------------+----------------+--------------+------------+
|   499510 |       548429 | 2011-11-23     | 2011-11-23   | 1976-01-01 |
+----------+--------------+----------------+--------------+------------+
|   499510 |       548427 | 2008-07-03     | 2008-07-03   | 1976-01-01 |
+----------+--------------+----------------+--------------+------------+
|   499510 |       548431 | 2001-05-01     | 1976-01-01   | 1976-01-01 |
+----------+--------------+----------------+--------------+------------+
|   499510 |       548430 | 1998-10-08     | 1998-10-08   | 1998-10-08 |
+----------+--------------+----------------+--------------+------------+

谢谢！

Answer 1

这是一种使用CTE编译传递关系列表的方法。一个CTE以递归方式定义从FromMembershipID到ToMembershipID的关系。第二个CTE在相反方向做同样的事情 - 这样，你可以将结果组合成第三个CTE，列出成员之间的每个传递关系。

例如，在第一个结果集中，20 =＆gt; 19和19 =＆gt;在图17中，反之，17 =＆gt; 19和19 =＆gt; 20，所以你得到：

然后，您可以使用该列表传递关系来获取成员资格的最小CServiceDate。

这为两组样本数据提供了正确的输出。如果您有更多数据，您可能会遇到100级递归限制，但您可以配置它。或者找到更好的解决方案:)但从技术上讲，这可行：

;with cte_trans_relationships (frommembershipid, tomembershipid)
as
(
    select frommembershipid, tomembershipid
    from @transfer
    union all
    select c.frommembershipid, t.tomembershipid
    from cte_trans_relationships c
    inner join @transfer t on c.tomembershipid = t.frommembershipid
),
cte_trans_relationships2 (tomembershipid, frommembershipid)
as
(
    select tomembershipid, frommembershipid
    from @transfer
    union all
    select c.tomembershipid, t.frommembershipid
    from cte_trans_relationships c
    inner join @transfer t on c.frommembershipid = t.tomembershipid
),
cte_trans_all (m1, m2)
as
(
    select distinct frommembershipid m1, tomembershipid m2
    from cte_trans_relationships c
    union 
    select distinct tomembershipid, frommembershipid
    from cte_trans_relationships2 c2    
)
select m.personid, m.membershipid, m.membershipdate, m.cservicedate, 
    case when sq.cservicedate < cservicedate1 and sq.cservicedate < cservicedate2 then sq.cservicedate
    when cservicedate1 < sq.cservicedate and cservicedate1 < cservicedate2 then cservicedate1
    else cservicedate2 end as ECSD
from @memberships m
inner join 
(
    select m.personid, m.membershipid, isnull(m.cservicedate, dateadd(year, 100, getdate())) as cservicedate, 
    isnull(min(m1.cservicedate), dateadd(year, 100, getdate())) as cservicedate1,
    isnull(min(m2.cservicedate), dateadd(year, 100, getdate())) as cservicedate2
    from @memberships m
    left join cte_trans_all sq_trans1 on m.membershipid = sq_trans1.m1
    left join @memberships m1 on sq_trans1.m2 = m1.membershipid and m1.membershipdate < m.membershipdate
    left join cte_trans_all sq_trans2 on m.membershipid = sq_trans2.m1
    left join @memberships m2 on sq_trans2.m2 = m2.membershipid and m2.membershipdate < m.membershipdate
    group by m.personid, m.membershipid, m.cservicedate
)sq on m.personid = sq.personid and m.membershipid = sq.membershipid

以下是用于测试的示例DDL / DML语句：

declare @memberships table (personid int, membershipid int, membershipdate datetime, cservicedate datetime)
insert into @memberships values (1, 15, '8/1/2016', '8/27/2017')
insert into @memberships values (1, 16, '3/25/2016', '9/1/2000')
insert into @memberships values (1, 17, '12/6/2011', '5/15/1995')
insert into @memberships values (1, 18, '1/12/2009', '2/28/1998')
insert into @memberships values (1, 19, '4/8/2016', '7/10/1994')
insert into @memberships values (1, 20, '6/11/2010', '11/12/1997')
--insert into @memberships values (499510, 548426, '9/29/2014', '9/29/2014')
--insert into @memberships values (499510, 548428, '1/29/2014', '1/29/2014')
--insert into @memberships values (499510, 548425, '5/28/2012', '5/28/2012')
--insert into @memberships values (499510, 548429, '11/23/2011', '11/23/2011')
--insert into @memberships values (499510, 548427, '7/3/2008', '7/3/2008')
--insert into @memberships values (499510, 548431, '5/1/2001', '1/1/1976')
--insert into @memberships values (499510, 548430, '10/8/1998', '10/8/1998')

declare @transfer table (tid int, pid int, frommembershipid int, tomembershipid int)
insert into @transfer values (1, 1, 16, 15)
insert into @transfer values (2, 1, 18, 17)
insert into @transfer values (3, 1, 19, 17)
insert into @transfer values (4, 1, 20, 18)
insert into @transfer values (5, 1, 20, 19)
--insert into @transfer values (10664, 499510, 548430, 548431)
--insert into @transfer values (10665, 499510, 548431, 548427)
--insert into @transfer values (10666, 499510, 548427, 548429)
--insert into @transfer values (10667, 499510, 548429, 548425)
--insert into @transfer values (10668, 499510, 548425, 548428)
--insert into @transfer values (10669, 499510, 548428, 548426)
--insert into @transfer values (13085, 499510, 548430, 548427)
--insert into @transfer values (13086, 499510, 548427, 548425)
--insert into @transfer values (13087, 499510, 548425, 548426)
--insert into @transfer values (13088, 499510, 548431, 548429)
--insert into @transfer values (13089, 499510, 548429, 548428)

以下是2个结果集：

personid  membershipid  membershipdate    cservicedate  ECSD
1         15            2016-08-01        2017-08-27    2000-09-01
1         16            2016-03-25        2000-09-01    2000-09-01
1         17            2011-12-06        1995-05-15    1995-05-15
1         18            2009-01-12        1998-02-28    1998-02-28
1         19            2016-04-08        1994-07-10    1994-07-10
1         20            2010-06-11        1997-11-12    1997-11-12

personid    membershipid    membershipdate  cservicedate    ECSD
499510      548425          2012-05-28      2012-05-28      1976-01-01
499510      548426          2014-09-29      2014-09-29      1976-01-01
499510      548427          2008-07-03      2008-07-03      1976-01-01
499510      548428          2014-01-29      2014-01-29      1976-01-01
499510      548429          2011-11-23      2011-11-23      1976-01-01
499510      548430          1998-10-08      1998-10-08      1998-10-08
499510      548431          2001-05-01      1976-01-01      1976-01-01

SQL Server查询根据传递关系查找最小日期

1 个答案: