代码打字 · SQL
Recursive CTE
Walk a category tree from the root down.
难度: 高级 · 11 行 · 许可: public-domain
WITH RECURSIVE category_tree AS (
SELECT id, name, parent_id, 0 AS depth
FROM categories
WHERE parent_id IS NULL
UNION ALL
SELECT c.id, c.name, c.parent_id, t.depth + 1
FROM categories AS c
INNER JOIN category_tree AS t
ON c.parent_id = t.id
时间0:00
速度 (WPM)0.0
准确率100.0%
错误0
实时键盘
下一个键: W | 上一个键: -
进度: 0.0%
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