Question

您好我有下表：

表格代码

  A     B     C     D
test    10    1     NEW
test2   1     5     NEW
test3   5     2     OLD
test4   40    3     NEW
test5   8     7     NEW
test6   7     9     OLDER

结果应该是

  A        B      C     D      E
test     10      1     NEW    OLD
test2    1       5     NEW    OLD
test3    5       2     OLD
test4    40      3     NEW
test5    8       7     NEW   OLDER
test6    7       9     OLDER

逻辑：

如果D为NEW，我检查C并查看该值是否在B中。如果没有，那就完成了那一行。如果有一个条目，我检查D是否为NEW，如果是，如果新的C在另一行的B中，依此类推，直到我发现C值为B而D为NEW。我不需要取这个值并把它放在受该saerch影响的其他行的D列中。

我有什么：

with CODE (A, B, C, D, E) AS
(SELECT Original.A, Original.B, Original.C, Original.D, '' 
from myschema.basetable Original where Original.D = 'CORIPD'
UNION ALL
Select lookup.A, lookup.B, lookup.C, lookup.D, '' 
from CODE Original, myschema.basetable lookup 
where Original.A = lookup.A and Original.C =  lookup.B
UNION ALL
Select lookup_next.A, lookup_next.B, lookup_next.C, '' D, lookup_next.D E
from CODE Original, myschema.basetable lookup_next 
where Original.A = lookup_next.A and Original.C =  lookup_next.B and lookup_next.C IS NULL
)
select A, B, C, D, E from CODE 
order by A, C, D

到目前为止的结果：

  A        B      C     D      E
test     10      1     NEW    
test2    1       5     NEW    
test3    5       2     OLD
test3    5       2            OLD
test4    40      3     NEW
test5    8       7     NEW   
test6    7       9     OLDER
test6    7       9            OLDER

系统是Windows IBM DB2 10.5

感谢您提供的任何帮助。

Answer 1

一种可能的解决方案 - 我在我的例子中使用了rectest作为表格ame

with temp (i,a,b,c,d,e) as (
select 1 as i, a,b,c,d, cast('-' as varchar(10)) as e
  from rectest 
 where D <> 'NEW'
union all
select t.i + 1 as i, r.a, r.b, r.c, r.d
     , case when t.i = 1 then t.d
            when t.i > 1 and t.e <> '-' then t.e
            else '-' 
       end as e            
  from temp t,
       rectest r
 where t.b = r.c
 and t.i < 5
)
, temp2 as (
select a,b,c,d,e from temp
)
select * from temp2
union all
select a,b,c,d, '-' as e from rectest 
 where a not in (select a from temp2) 
order by a;

第二个CTE只需要获取没有dependend行的行（这些行不属于recorsion - 在你的示例test4中。

递归查询和汇总行DB2

1 个答案: