Question

我有一个表“ TB_Population”，其中包含有关世界各地人口的一些记录。这时我想计算特定行中每个标题的人口并演示该表中的每个级别。

我有这张表，其中包含以下数据：

ID     TITLE        PARENT_ID    POPULATION

1      WORLD                         10    
2      AFRICA         1              5  
3      ASIA           1              10
4      EUROPE         1              4
5      GERMANY        4              6
6      FRANCE         4              10
7      ITALY          4              4
8      JAPAN          3              6
9      MORROCO        2              1
10     SPAIN          4              9
11     INDIA          3              8  
12     PORTUGAL       4              2
13     USA            14             10         
14     AMERICA        1              10             
15     NEWYORK        13             5

预期输出表应如下

   ID     TITLE     POPULATION       LEVEL

    1      WORLD        100             1   
    2      AFRICA       6               2
    3      ASIA         24              2
    4      EUROPE       35              2
    5      GERMANY      6               3
    6      FRANCE       10              3
    7      ITALY        4               3
    8      JAPAN        6               3
    9      MORROCO      1               3   
    10     SPAIN        9               3
    11     INDIA        8               3
    12     PORTUGAL     2               3
    13     USA          15              3
    14     AMERICA      25              2
    15     NEWYORK      5               4

感谢和问候

Answer 1

我在这里看到的棘手部分是您希望标题的级别从“底部到顶部”，而人口从“顶部到底部”。例如，AMERICA的级别必须为2，这意味着必须从AMERICA-> WORLD来测量LEVEL，但是AMERICA的人口必须是25从AMERICA-> NEWYORK来衡量的总和。所以，我尝试了这个：

SELECT TOP_TO_BOTTOM.TITLE_ALIAS, TOP_TO_BOTTOM.TOTAL_POPULATION, BOTTOM_TO_TOP.MAX_LEVEL FROM
(SELECT TITLE_ALIAS, SUM(POPULATION) AS "TOTAL_POPULATION" FROM
(SELECT CONNECT_BY_ROOT TITLE AS "TITLE_ALIAS", POPULATION
      FROM TB_POPULATION 
      CONNECT BY PRIOR ID = PARENT_ID) 
GROUP BY TITLE_ALIAS) "TOP_TO_BOTTOM"
INNER JOIN
(SELECT TITLE_ALIAS, MAX(LEV) AS "MAX_LEVEL" FROM
(SELECT CONNECT_BY_ROOT TITLE AS "TITLE_ALIAS", LEVEL AS "LEV"
      FROM TB_POPULATION 
      CONNECT BY PRIOR PARENT_ID = ID) 
GROUP BY TITLE_ALIAS) "BOTTOM_TO_TOP"
ON
BOTTOM_TO_TOP.TITLE_ALIAS = TOP_TO_BOTTOM.TITLE_ALIAS
ORDER BY BOTTOM_TO_TOP.MAX_LEVEL;

您可以在此处查看仿真：https://rextester.com/HFTIH47397。希望这对您有帮助

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