原文地址
mysql递归查询，mysql中从子类ID查询所有父类（做无限分类经常用到）由于mysql 不支持类似 oracle with ...connect的 递归查询语法之前一直以为类似的查询要么用存储过程要么只能用程序写递归查询.现在发现原来一条sql语句也是可以搞定的先来看数据表的结构如下：id name parent_id --------------------------- 1 Home 0 2 About 1 3 Contact 1 4 Legal 2 5 Privacy 4 6 Products 1 7 Support 1 我要的要求是根据一个分类ID（这个分类ID可能是一个子分类），得到所有的父分类，下面是相应的SQL：SELECT T2.id, T2.name FROM ( SELECT @r AS _id, (SELECT @r := parent_id FROM table1 WHERE id = _id) AS parent_id, @l := @l + 1 AS lvl FROM (SELECT @r := 5, @l := 0) vars, table1 h WHERE @r <> 0) T1 JOIN table1 T2 ON T1._id = T2.id ORDER BY T1.lvl DESC 代码@r := 5标示查询id为5的所有父类。结果如下1, ‘Home’2, ‘About’4, ‘Legal’5, ‘Privacy’
转载于:https://www.cnblogs.com/mendeliang/p/5070825.html
