在每个级别的层次结构查询总和

Question

我有以下表结构。我想从TAB2的每个级别获得总和。

TAB1在级别列中存储层次结构。

TAB1 
----- ----- ---- ---- 
KEY L1  L2 L3 
---- ----- ----- ---- 
A  A 
B  A  B 
C  A  B  C 
D  A  B  D 

TAB2 
----- 
KEY TC 
---- ---- 
A  10 
B  11 
C  6 
D  12 
X  11 

Expected Output: 

KEY SUM 
---- ---- 
A 39 
B 29 
C 6 
D 12 
X 11 

这里是SQLFiddle链接：LINK TO FIDDLE

Answer 1

甲骨文设置

Create table TAB1 (pKey varchar2(10),level1 varchar2(10),level2 varchar2(10),level3 varchar2(10),level4 varchar2(10)); 
insert into TAB1(pKey,level1) values('A','A'); 
insert into TAB1(pKey,level1,level2) values('B','A','B'); 
insert into TAB1(pKey,level1,level2,level3) values('C','A','B','C'); 
insert into TAB1(pKey,level1,level2,level3) values('D','A','B','D'); 

Create table TAB2 (pKey varchar(10), tc integer); 
insert into TAB2(pKey,tc) values('A',10); 
insert into TAB2(pKey,tc) values('B',11); 
insert into TAB2(pKey,tc) values('C',6); 
insert into TAB2(pKey,tc) values('D',12); 
insert into TAB2(pKey,tc) values('X',11); 

查询：

SELECT t2.pKey, 
     SUM(COALESCE(t4.TC, t2.tc)) AS tc 
FROM tab2 t2 
     LEFT OUTER JOIN 
     tab1 t1 
     ON (t2.pKey = t1.pKey) 
     LEFT OUTER JOIN 
     tab1 t3 
     ON ( t1.level1 = t3.level1 
      AND (t1.level2 IS NULL OR t1.level2 = t3.level2) 
      AND (t1.level3 IS NULL OR t1.level3 = t3.level3) 
      AND (t1.level4 IS NULL OR t1.level4 = t3.level4)) 
     LEFT OUTER JOIN 
     tab2 t4 
     ON (t3.pKey = t4.pKey) 
GROUP BY t2.pKey; 

输出：

PKEY    TC 
---------- ---------- 
D     12 
A     39 
B     29 
C     6 
X     11 

Answer 2

在下面提供的解决方案（包括输入数据作为因式分解的子查询），第一我展示如何使用unpivot和附加操作正常化tab1（结果是因子分解子查询n为“n ormalized” ）。然后，如果你有正常形式的数据，则可以通过直接应用我的代码底部显示的标准分层查询来获得输出结果。

with 
    tab1 (key, L1, L2, L3) as (
     select 'A', 'A', null, null from dual union all 
     select 'B', 'A', 'B' , null from dual union all 
     select 'C', 'A', 'B' , 'C' from dual union all 
     select 'D', 'A', 'B' , 'D' from dual 
    ), 
    tab2 (key, TC) as (
     select 'A', 10 from dual union all 
     select 'B', 11 from dual union all 
     select 'C', 6 from dual union all 
     select 'D', 12 from dual union all 
     select 'X', 11 from dual 
    ), 
    unpiv (key, l, ancestor) as (
     select key, to_number(substr(lv, 2)), ancestor from tab1 
     unpivot (ancestor for lv in (L1, L2, L3)) 
    ), 
    d (key, depth) as (
     select key, max(l) 
     from unpiv 
     group by key 
    ), 
    n (child, parent, TC) as (
     select d.key, u.ancestor, tab2.TC 
     from unpiv u 
      right outer join d 
       on u.key = d.key and u.l = d.depth - 1 
      left outer join tab2 
       on d.key = tab2.key 
    ) 
SELECT key, sum(TC) as sum_TC 
from (
    select connect_by_root child as key, TC 
    from n 
    connect by prior child = parent 
) 
group by key 
order by key; 

一路上，在unpiv，我已经把所有的父子关系，所以我可以直接加入与tab2上unpiv.key = tab2.key和ancestor（类似于MT0的解决方案）总结TC分组。相反，我想演示两个单独的步骤：（1）规范化tab1和（2）在规范化表上使用分层查询是多么容易。

输出：

KEY  SUM_TC 
--- ---------- 
A   39 
B   29 
C   6 
D   12