示例
示例
SELECT user_id, created_at,
NTH_VALUE(created_at, 2) OVER (
PARTITION BY user_id
ORDER BY created_at
ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING
) AS second_order_at
FROM orders;| 语法 | NTH_VALUE(expr, n) |
|---|---|
| 帧 | 建议显式写完整帧，否则受默认帧限制 |
| 超出 | 返回 NULL |