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  • postpreSQL和oracle数据库的递归

    oracle:

    --包含自身

    select *
    from sec_org
    start with org_id ='9767FA56D52680AEE043C0A8670580AE' --开始节点
    connect by prior org_id = parent_org_id --父子关系

    --不包含自身

    select *
    from sec_org
    start with parent_org_id ='9767FA56D52680AEE043C0A8670580AE' --开始节点
    connect by prior org_id = parent_org_id --父子关系

    在实际中,可能需要对数据进行过滤,但是在递归查询中,不能进行过滤,可以先对数据进行过滤,使用过滤的数据进行递归

    select *
      from (select * from sec_org where status = 'enable')
     start with org_id = '9767FA56D52680AEE043C0A8670580AE' --开始节点
    connect by prior org_id = parent_org_id --父子关系

    postpreSQL

    --包含自身
    WITH RECURSIVE cte AS ( SELECT * FROM sec_org WHERE org_id = '9767FA56D52680AEE043C0A8670580AE' AND status = 'enable' UNION SELECT o.* FROM sec_org o INNER JOIN cte ON o.parent_org_id = cte.org_id WHERE o.status = 'enable' ) SELECT * FROM cte
    --不包含自身
    WITH RECURSIVE cte AS ( SELECT * FROM sec_org WHERE org_id = '9767FA56D52680AEE043C0A8670580AE' AND status = 'enable' UNION SELECT o.* FROM sec_org o INNER JOIN cte ON o.parent_org_id = cte.org_id WHERE o.status = 'enable' ) SELECT * FROM cte
    WHERE cte.org_id!='9767FA56D52680AEE043C0A8670580AE'

    1.首先执行  SELECT * FROM sec_org WHERE org_id = '9767FA56D52680AEE043C0A8670580AE' AND status = 'enable'

    2.执行外层的的select * from cte,此时有一条记录

    3.执行union后面的语句

    4.若3查询出数据,则重复2,3,一直递归,直至3查询的数据为

     
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  • 原文地址:https://www.cnblogs.com/cdblogs/p/7895395.html
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