--查询Id为1的所有子节点层数的数量
;with cte as ( select id,parentId,0 as Leave from _TestLeave where id = 1 --要查询的节点 union all select a.id,a.parentId,b.Leave + 1 as Leave from _TestLeave a join cte b on a.parentId = b.id and b.Leave < 6 --层数 ) select leave,count(*) from cte where leave > 0 group by Leave
原文：https://www.cnblogs.com/epsoft/p/9091695.html