SELECT * FROM CATEGORY c 
CONNECT BY PRIOR c.id = c.category_parent_id  
START WITH c.id = 123

?上面的sql查询 category_parent_id?是 123 的结果集。

SELECT * FROM CATEGORY c 
CONNECT BY PRIOR c.category_parent_id = c.id  
START WITH c.id = 123

?上面的sql查询是 123 父结点的结果集。