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row_number() over (partition by..order by...)分组排序

例： select regexp_substr(p.attributename, '[^,]+',1,level) c1 from tablename p connect by level <= length(p.attributename) - length(replace(p.attributename,',','')) + 1 结果

1、select id from tablename start with id='idNum' connect by prior id = parentId;- -自顶向下查询 2、select id from tablename start with id='idNum' connect by id = prior parentId;- -自底向上查询 1、prior在左边，自顶向下查询。