获取父节点的所有子节点

Question

我有一个从 Kartik Tree Manager 渲染的 treeview。下面是我的树视图

Table

我想做什么？

我想select通过MySQL查询Floor-1的所有子节点

我试过运行如下查询

SELECT * FROM `mdc_node` m 
WHERE m.`lft` = 11-2

输出

期望输出

我想要以下输出

------------------------------------------------------------
| `id` | `root` | `lft` | `rgt` | `lvl` | `name`   | 'icon' |
------------------------------------------------------------
| 3    |    1   |   3   |    4  |   2   |GIS Office| folder |
| 4    |    1   |   5   |    6  |   2   |   Ali    |  user  |
| 5    |    1   |   7   |    8  |   2   |   Usman  |  user  |
| 6    |    1   |   9   |    10 |   2   |  Faisal  |  user  |
------------------------------------------------------------

下面是我的SQLFiddle

Node Table

我要select父节点下的所有子节点

Answer 1

I want to select all the child nodes of Floor-1 via MySQL query

I want the following output

select * from mdc_node;

SELECT t1.id, t1.root, t1.lft, t1.rgt, t1.lvl, t1.name, t1.icon
-- from 1st copy of a table
FROM mdc_node t1
-- join 2nd copy of a table used for to get the info about needed parent
JOIN mdc_node t2
-- child nodes left and right are between left and right of their  parent
                ON t1.lft BETWEEN t2.lft AND t2.rgt
-- we need only the next level
                AND t1.lvl = t2.lvl + 1
-- specify parent
WHERE t2.name = 'Floor-1';

fiddle

唯一的问题 - 我不明白为什么 icon 行 id=3 在输出中是 'folder' 而在源数据中是 'user'。