如何从oracle中的层次结构中查询答案

【问题标题】：How to query from a hierarchy in oracle如何从oracle中的层次结构中查询
【发布时间】：2012-05-26 19:46:29
【问题描述】：

我使用的 Oracle 数据库包含客户、连锁店和活动表。像这样（精简）：

TABLE CUSTOMER 
  ACCOUNTNUMBER   VARCHAR2
  CHAIN           VARCHAR2
  CATEGORY        VARCHAR2

TABLE CHAIN
  CODE            VARCHAR2
  PARENTCHAIN     VARCHAR2

TABLE CAMPAIGN
  ID              NUMBER
  DISCOUNT        NUMBER

TABLE CAMPAIGN_ELIGIBILITY
  CAMPAIGNID      NUMBER   --ID of the campaign
  ACCOUNTNUMBER   VARCHAR2 --Customer included in the campaign
  CHAINCODE       VARCHAR2 --Chain included in the campaign
  CUSTCATCODE     VARCHAR2 --Customercategory included in the campaign

客户可以通过其定义的客户组或作为连锁店的成员，有资格参加特定的活动（基于帐号）。

我使用此查询来查找对给定客户有效的所有广告系列：

select * from campaign where id in
(
  select unique campaignid from campaign_eligibility where 
    accountnumber=:accountnumber
  union
  select unique campaignid from campaign_eligibility where 
    chaincode = 
      (select chain from debtable where accountnumber=:accountnumber)
  union
  select unique campaignid from campaign_eligibility where 
    custcatcode =
      (select category from customer where accountnumber=:accountnumber)
)

现在，假设客户“Popeye Spinach Empire”是“Spinach Dealers Inc.”连锁店的成员，该连锁店又是更大的连锁店“GreenFud R US”的一部分，而后者又是链“FoAC”。如果有针对“GreenFud R US”的广告系列，Popeye 就有资格参与该广告系列。我的查询将仅返回已明确添加 Popeye 或以“Spinach Dealers Inc.”为目标的广告系列

如何修改我的查询以包含客户间接参与的营销活动？

【问题讨论】：

标签： sql oracle hierarchy

【解决方案1】：

WITH    chains AS
        (
        SELECT  code
        FROM    chain c
        START WITH
                c.code IN
                (
                SELECT  chain
                FROM    campaign_eligibility
                WHERE   accountnumber = :acc
                UNION ALL
                SELECT  chain
                FROM    customer c
                JOIN    campaign_eligibility ce
                ON      ce.custcatcode = c.category
                WHERE   accountnumber = :acc
                UNION ALL
                SELECT  chain
                FROM    customer
                WHERE   accountnumber = :acc
                )
        CONNECT BY
                c.code = PRIOR c.parentchain
        ) ch
SELECT  *
FROM    campaign
WHERE   c.id IN
        (
        SELECT  campaignid
        FROM    chains 
        JOIN    campaign_eligibility ce
        ON      ce.chaincode = c.code
        )

【讨论】：