<转>mysql 树查询话语

<转>mysql 树查询语句
原链接：http://skudy.iteye.com/blog/1434254
求下级所有节点

SELECT      *  FROM      tree t  WHERE      NOT EXISTS(          SELECT              1          FROM              tree t1,              tree t2          WHERE              t1.id= t2.pid          AND t1.id= t.pid      )