google-bigquery - BigQuery：获取特定行之前的所有行

Question

我有一个名为“t1”的表

这是样本数据。

表 t1：

+------+---------------+--------------------------------------+
| row  | event_name    | status                               |
+------+---------------+--------------------------------------+
| 1    | heartbeat     | null                                 |
| 2    | heartbeat     | null                                 |
| 3    | screen_status | enter_background                     |
| 4    | heartbeat     | null                                 |
| 5    | heartbeat     | null                                 |
| 6    | heartbeat     | null                                 |
| 7    | heartbeat     | null                                 |
| 8    | heartbeat     | null                                 |
| 9    | heartbeat     | null                                 |
| 10   | heartbeat     | null                                 |
| 11   | heartbeat     | null                                 |
| 12   | heartbeat     | null                                 |
| 13   | heartbeat     | null                                 |
| 14   | screen_status | enter_foreground                     |
| 15   | heartbeat     | null                                 |
| 16   | heartbeat     | null                                 |
| ...  | ...           | null                                 |
+------+---------------+--------------------------------------+

每当“状态”列更改为新值时，我想用该新值填充空值。

例如 ：

+------+---------------+--------------------------------------+
| row  | event_name    | status                               |
+------+---------------+--------------------------------------+
| 1    | heartbeat     | null                                 |
| 2    | heartbeat     | null                                 |
| 3    | screen_status | enter_background                     |
| 4    | heartbeat     | enter_background                     |
| 5    | heartbeat     | enter_background                     |
| 6    | heartbeat     | enter_background                     |
| 7    | heartbeat     | enter_background                     |
| 8    | heartbeat     | enter_background                     |
| 9    | heartbeat     | enter_background                     |
| 10   | heartbeat     | enter_background                     |
| 11   | heartbeat     | enter_background                     |
| 12   | heartbeat     | enter_background                     |
| 13   | heartbeat     | enter_background                     |
| 14   | screen_status | enter_foreground                     |
| 15   | heartbeat     | enter_foreground                     |
| 16   | heartbeat     | enter_foreground                     |
| ...  | ...           | ...                                  |
+------+---------------+--------------------------------------+

如何在 BigQuery 中做到这一点？

标签： google-bigquery