[使用递归查询ORACLE 11G查找客户之间的所有依赖项

Question

我正在尝试编写一个递归CTE，以便为所有其他客户提供“主要客户”，但是我不知道从哪里开始。

我已经创建了示例数据集和表结构：

create table T_CUSTOMER_RELATIONSHIP (CUST_ID VARCHAR2(10), OTHER_CUST_ID VARCHAR2(10))

insert into T_CUSTOMER_RELATIONSHIP values ('CUST1', 'CUST1');
insert into T_CUSTOMER_RELATIONSHIP values ('CUST1', 'CUST2');
insert into T_CUSTOMER_RELATIONSHIP values ('CUST1', 'CUST3');
insert into T_CUSTOMER_RELATIONSHIP values ('CUST1', 'CUST4');
insert into T_CUSTOMER_RELATIONSHIP values ('CUST5', 'CUST5');
insert into T_CUSTOMER_RELATIONSHIP values ('CUST5', 'CUST4');
insert into T_CUSTOMER_RELATIONSHIP values ('CUST5', 'CUST6');
insert into T_CUSTOMER_RELATIONSHIP values ('CUST7', 'CUST7');
insert into T_CUSTOMER_RELATIONSHIP values ('CUST7', 'CUST6');
insert into T_CUSTOMER_RELATIONSHIP values ('CUST8', 'CUST8');
insert into T_CUSTOMER_RELATIONSHIP values ('CUST8', 'CUST9');
insert into T_CUSTOMER_RELATIONSHIP values ('CUST8', 'CUST10');

commit;

““主要”客户记录具有相同的CUST_ID和OTHER_CUST_ID值（因此... CUST_ID1，CUST_ID5，CUST_ID7，CUST_ID8是“主要”客户）

我想按如下方式获得（例如）CUST_ID1的结果集：

CUST_ID   OTHER_CUST_ID
CUST1     CUST2
CUST1     CUST3
CUST1     CUST4
CUST1     CUST5
CUST1     CUST6
CUST1     CUST7

...这将允许我设置一个提取脚本，该脚本将直接或通过与另一主要客户（及其相关客户，因此与之建立共同关系）为与CUST1相关的所有客户提取所有详细信息。递归）

这可能吗？

Answer 1

您可以使用分层查询：

SELECT DISTINCT
       CONNECT_BY_ROOT( cust_id ) AS cust_id,
       other_cust_id
FROM   T_CUSTOMER_RELATIONSHIP
START WITH cust_id = 'CUST1'
CONNECT BY NOCYCLE
       (  PRIOR other_cust_id IN ( cust_id, other_cust_id )
       OR PRIOR cust_id       IN ( cust_id, other_cust_id ) )
ORDER BY cust_id, other_cust_id;

输出：

CUST_ID | OTHER_CUST_ID：------ | ：------------CUST1 |客户1CUST1 |客户2CUST1 |客户3CUST1 |客户4CUST1 |客户5CUST1 |客户6CUST1 |客户7

db <>小提琴here