SQL中的递归层次查询

Question

我有下表

Tbl矩阵

ID   ApproverId
--------------------
1    4
2    7
7    8
4    5
5    6

我想编写一个自联接查询以返回以下任何ApproverId的输出

如果我将ApproverId传递为6

输出应为

ID
---
5
4
1

如果我将ApproverId传递为8

输出应为

ID
---
7
2

Answer 1

使用递归查询

with rcte as
(
    select id from tblMatrix where approverId = 8
    union all
    select tblMatrix.id 
    from tblMatrix
    join rcte on tblMatrix.approverid = rcte.id
)
select * from rcte

dbfiddle演示