与组排名

Question

我的table1是这样的

Dept    Class   Dept1   Class1      date
NULL    NULL     a      history     02-2020
NULL    NULL     a      bio         02-2020
a       math    NULL    NULL        02-2020
a       chemi   NULL    NULL        02-2020
a       history NULL    NULL        02-2020
b       PE      NULL    NULL        03-2020
b       Music   NULL    NULL        03-2020
b       Sport   NULL    NULL        03-2020
NULL    NULL     b      Cook        03-2020
c       Psy     NULL    NULL        04-2020

我们可以查询看起来像这样的吗

Dept    Class   Dept1   Class1      date
a       math     a      history     02-2020
a       chemi    a      bio         02-2020
a       history NULL    NULL        02-2020
NULL    NULL    NULL    NULL        02-2020
NULL    NULL    NULL    NULL        02-2020
b       PE      b       Cook        03-2020
b       Music   NULL    NULL        03-2020
b       Sport   NULL    NULL        03-2020
NULL    NULL    NULL    NULL        03-2020
c       Psy     NULL    NULL        04-2020

目标尝试按 Dept、Dept1 和日期获取记录组
您可以使用 nvarchar 或整数的任何字段
我的查询并不能正常工作

select coalesce(sm.dept, su.dept1) as dept,
               sm.class,
               su.class1,
               sm.date
        from 
                (select distinct w.*, 
                 row_number() over (partition by dept order by [date] asc) as seqnum
                 from table1 w
                 ) sm
          full join
                 (select w.*,
                 row_number() over (partition by dept1 order by [date] asc) as seqnum
                  from table1 w

                 ) su

         on sm.dept = su.dept1 and sm.seqnum = su.seqnum

Answer 1

是的。 . . 您似乎希望“组”中的列按日期对齐。 这是一种方法：

select date, max(dept), max(class), max(dept1), max(class1)
from ((select date, row_number() over (order by dept) as seqnum,
              dept, null as class, null as dept1, null as class1
       from t
       where dept is not null
      ) union all
      (select date, row_number() over (order by class) as seqnum,
              null as dept, class, null as dept1, null as class1
       from t
       where class is not null
      ) union all
      (select date, row_number() over (order by dept1) as seqnum,
              null, null as class, dept1, null as class1
       from t
       where dept1 is not null
      ) union all
      (select date, row_number() over (order by class1) as seqnum,
              null as dept, null as class, null as dept1, class1
       from t
       where class1 is not null
      )
     ) x
group by date, seqnum;

Answer 2

我了解您想按日期订购，然后按部门、class、部门1、类1 列订购。 在 SQL 服务器中，默认情况下 NULL 出现在顶部。 因此，我将 NULL 值替换为 ZZZZZ 以使它们最终出现。 您可以将 ZZZZZ 替换为大的 varchar 字段，该字段不会出现在您的部门、class、dept1、class1 字段中。

DECLARE @dept table(dept varchar(50),class varchar(50),dept1 varchar(50),class1 varchar(50),datev varchar(50))

insert into @dept VALUES
(NULL    ,NULL        ,'a'     ,'history'    ,'02-2020')
,(NULL    ,NULL        ,'a'    , 'bio'        ,'02-2020')
,('a'       ,'math'    ,NULL   , NULL        ,'02-2020')
,('a'       ,'chemi'   ,NULL   , NULL        ,'02-2020')
,(null       ,NULL   ,NULL   , NULL        ,'02-2020')
,(null       ,NULL   ,NULL   , NULL        ,'02-2020')
,('a'       ,'history' ,NULL   , NULL        ,'02-2020')
,('b'       ,'PE'      ,NULL   , NULL        ,'03-2020')
,('b'       ,'Music'   ,NULL   , NULL        ,'03-2020')
,('b'       ,'Sport'   ,NULL   , NULL        ,'03-2020')
,(NULL    ,NULL        ,'b'     ,'Cook'        ,'03-2020')
,(null       ,NULL   ,NULL   , NULL        ,'03-2020')
,('c'       ,'Psy'     ,NULL    ,NULL        ,'04-2020');

SELECT  DEPT, class, dept1, class1, datev 
from
(
SELECT *,ROW_NUMBER() over(order by datev,isnull(dept,'ZZZZZ'),isnull(class,'ZZZZZ'),isnull(dept1,'ZZZZZ'),isnull(class1,'ZZZZZ') ) as rnk FROM @dept
) AS T
order by rnk

+------+---------+-------+---------+---------+
| DEPT |  class  | dept1 | class1  |  datev  |
+------+---------+-------+---------+---------+
| a    | chemi   | NULL  | NULL    | 02-2020 |
| a    | history | NULL  | NULL    | 02-2020 |
| a    | math    | NULL  | NULL    | 02-2020 |
| NULL | NULL    | a     | bio     | 02-2020 |
| NULL | NULL    | a     | history | 02-2020 |
| NULL | NULL    | NULL  | NULL    | 02-2020 |
| NULL | NULL    | NULL  | NULL    | 02-2020 |
| b    | Music   | NULL  | NULL    | 03-2020 |
| b    | PE      | NULL  | NULL    | 03-2020 |
| b    | Sport   | NULL  | NULL    | 03-2020 |
| NULL | NULL    | b     | Cook    | 03-2020 |
| NULL | NULL    | NULL  | NULL    | 03-2020 |
| c    | Psy     | NULL  | NULL    | 04-2020 |
+------+---------+-------+---------+---------+