sql get parent cat by child id

原來呢個網有教

http://dev.mysql.com/tech-resources/articles/hierarchical-data.html

我再改一下

#get the path by child id, only one row,

SELECT t1.name, t2.name, t3.name

FROM category AS t1

LEFT JOIN category AS t2 ON t2.parent = t1.category_id

LEFT JOIN category AS t3 ON t3.parent = t2.category_id

WHERE (t3.category_id = [child_id])

#get the path by child id, row number = member of family

SELECT t1.* FROM category AS t1

LEFT JOIN category AS t2 ON t2.parent = t1.category_id

LEFT JOIN category AS t3 ON t3.parent = t2.category_id

WHERE 

(t1.category_id = [child_id] OR t2.category_id = [child_id] OR t3.category_id = [child_id])

 ORDER BY t1.LEVEL